# Cav Plate Comparison



## TexasFlats (Mar 29, 2007)

I'm in the market for a new cavitation plate and it occurs to me that there are quite a few choices available. It looks like there are 2 basic types available, with minor variations of each type.

1. *Full coverage plate* - starts in front of the lower unit and continues past the prop.

Variations - 
1a. side fins are on the front of the plate only:

K&P Plate









Shallow Blaster









1b. side fins are full length

Nedski









Manta Ray









Boatright









1c. side fins are the back of the plate - over the prop:

Shallow Sport (?)









Fin angles vary - hard 90 degree, 45 degree, or gradual slope - any input on what has worked best for you?

1d. no side fins

Dargel









Dargel specifically states that a cav plate should not have side fins as it may adversely affect the steering.

1e. fin in the center of the plate

ShawWing









2. *Whale Tail style* - covers the top of the prop only.

Variations -
2a. flat with built in fins

Bob's









2b. curved - no fins

Tran











I'm not real excited about buying and installing 2 or 3 of them to get one that works, so I thought I'd ask you:

*Which cav plates have you had, or have now - and how do you like it?*



Notes:
1. Thanks to those whom I have "borrowed" pictures from.
2. My hull is a 15ft Shallow Sport Scooter / 90 E-Tec
3. I don't want to factor into this discussion whether the plate bolts to the motor or not. I want to find out what works, and then decide if it's worth drilling into the motor.

I know there have been a lot of threads about cav plates, but it's usually a tug of war between the Shallow Blaster and the Boatright plate - I wanted to see what else is available and what works.

TexasFlats


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## robul (Apr 26, 2007)

I was going to buy a cav plate for my dargel but I tried the nauticus trim tabs first and changed out the 3 blade for a 4 blade.. Never thought about a cav plate again.. Boat is perfect now. I was going to buy the boatright though.. Good luck in your search.


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## Slimshady (Jan 11, 2005)

Without out a plate, the SS tunnel has large amounts of water mist or spray the back of the boat and driver. I've tried to run without one and its no good. As far as brand, throw a dart. I've had the Fibertex, Shallow blaster, and Shallowsport on different boats. All worked the same. It seemed like the rubber nosecone piece on the Shallow blaster helped with fit and keeping grassing from getting caught between it and the motor. My buddies Boatright plate on a 20' no sides is extremely well made though. Whatever you choose, make sure it fits tight and does not vibrate or move on the skeg. It can eventually wear through and damage the lower unit. Good Luck!


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## locochon (Feb 16, 2005)

i have a 05 15' shallowsport with a 90 yamaha and i have a shallowblaster. they work good and you dont have to drill holes in your lower unit.


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## gregr1971 (Oct 28, 2005)

i have had great luck with the S.S. plate.


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## LA Cox (Oct 19, 2004)

I've had a Nedski on one boat...great plate but requires drilling into the lower unit.

Now I've got a Boatright plate...Love it no drilling.

Late,
Cox


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## wingnut (Jul 18, 2006)

I have a Nedski, Works well for me, its been on my motor for about 7 years now, I thought is was causing my motor to run hot at one time but it turned out to be my thermostats


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## 6.5 shooter dude (Jan 8, 2008)

I will only speak of the 2 that I have used. the shallow blaster was OK I will not buy another one it shakes around so much it ate 1/2 way through my motor. I now run the Trans plate and it holds the water around the prop very good..... I will buy again and it bolts to your motor no shaking around.


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## Slimshady (Jan 11, 2005)

Capt Jay Baker said:


> I will only speak of the 2 that I have used. the shallow blaster was OK I will not buy another one it shakes around so much it ate 1/2 way through my motor. I now run the Trans plate and it holds the water around the prop very good..... I will buy again and it bolts to your motor no shaking around.


I think any of the clamp style plates will damage the lower unit if loose. Its a matter of whether you want to drill holes in the cav plate. When installing the Shallowblaster, I would take a small ratchet strap around the back section pulling it tight together against the LU. I then drilled the holes for the end plate holding everything snug.


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## kenner27 (May 29, 2006)

cant go wrong with the boatright. i have it and it does great


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## Shocker (Jul 15, 2005)

Question: Which one works best for a cat hull?


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## Splash (Oct 22, 2004)

*had one made for me*

I had a clip on cavitation fiberglass plate which fell off - somewhere in a back lake. I drive an ultra cat and like to go real shallow for my reds. I had Gary Robertson at Espandre/Woodee Rods make one for me. Tried it out Sat and Sun this past weekend and am very pleased. This one bolts on and it made solid. This one won't come off like the initial clip on plate.


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## locochon (Feb 16, 2005)

my shallowblaster has never moved. they put 5200 marine sealant around it and its held up fine and never moved.


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## TexasFlats (Mar 29, 2007)

locochon said:


> i have a 05 15' shallowsport with a 90 yamaha and i have a shallowblaster. they work good and you dont have to drill holes in your lower unit.


loco - I had a Yamaha 90 before I repowered. Started with a Shallow Sport plate, which broke, then got the Nedski. Ned's plate is bulletproof.

How much clearance do you have between the tunnel and the front of the plate when the motor is tilted all the way down? Mine was pretty tight and I had to grind it down to get it to clear. It would still hit occasionally when underway.


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## TexasFlats (Mar 29, 2007)

robul said:


> I was going to buy a cav plate for my dargel but I tried the nauticus trim tabs first and changed out the 3 blade for a 4 blade.. Never thought about a cav plate again.. Boat is perfect now. I was going to buy the boatright though.. Good luck in your search.


Robul - I have looked at the Smart Tabs, but I'm not going to do them yet. 4-blade prop is on order though. I know I'll need the plate, so I'll do that first.
Do you think the tabs helped your holeshot?


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## crabbeater (Feb 9, 2006)

*cav plate*

the tran cav plate is curved down close to the prop to prevent blow out on the sides when taking off and turning. It keeps the water to the prop,where as the other plates just compresses the water downward and out when the boat is running, similar to trim tabs but mounted on the motor instead of the boat.


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## LBS (Sep 2, 2004)

> I think any of the clamp style plates will damage the lower unit if loose.


My shallow blaster did a little damage to my lower unit as well so I took a bicycle tire tube and wrapped it around lower unit where the shallow blaster slides on...no more wear.


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## Big Fish (Feb 4, 2005)

I have a Boatwright cav plate and it works great. I have not had any issues with it wearing or rubbing the cavitation plate on the motor.


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## SS Minnow (Nov 3, 2005)

Boatright bar none. it is the last plate you will need. i had a fiberglass one before and it flexed alot and started separating. the boatright works better with no flex and you don't have to drill into your motor.


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## dboram (Sep 27, 2004)

Just put a BoatRight on my new etec and love it. I went and saw Glen. He took the time to visit with me, explain the installation tips, and talk about how it should be set up to work best with my 21 Shallow Sport. You cannot go wrong with BoatRight.


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## gris (Feb 8, 2006)

*BoatRight*

Do yourself a big favor...get a BoatRight.

Please don't drill holes in your lower unit. One of my best friends has a Suzuki, that is cracking very badly from the holes drilled in it from his compression plate.


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## jmack (Dec 7, 2006)

Agree go with BoatRight !!



gris said:


> Do yourself a big favor...get a BoatRight.


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## stew1tx (Oct 15, 2004)

Tran's design is the absolute best I have ever used. I have had or used about every design out there and this works the best at holding water around the prop, especially in turns. I can not understand why shallow sport says that about plates with fins. It helps the directional flow of water which in turn enhances the turning ability of the boat. Kind of like adding a rudder to a flat bottom boat.


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## stew1tx (Oct 15, 2004)

AND, for a cat, NOTHING out there works better than a Tran style plate. BAR NONE, well none that I have utilized anyhow.


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## locochon (Feb 16, 2005)

i get plenty of clearance with the engine tucked all the way in.



TexasFlats said:


> loco - I had a Yamaha 90 before I repowered. Started with a Shallow Sport plate, which broke, then got the Nedski. Ned's plate is bulletproof.
> 
> How much clearance do you have between the tunnel and the front of the plate when the motor is tilted all the way down? Mine was pretty tight and I had to grind it down to get it to clear. It would still hit occasionally when underway.


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## kapman (Aug 3, 2006)

*Bob's Plate*

Anyone have any feedback on the Bob's Plate?


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## Texxan1 (Dec 31, 2004)

Ive had both a nedski ( on an etec) and shallow blaster on my zuke... The shallow blaster got loose and dug into my engine cav plate.. I had to drill one hole and install a tap screw to hold it in place.. No additional damage, but will say on my next motor i will NOT get a shallow blaster just because of this issue.

The nedski did great on my etec, but because of drilling into the motor i decided not to go with it on my new zuke.


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## Melon (Jun 1, 2004)

Can't stand someone who knows it all.....LOL But stew is right on that tran cav plate. I have tried three differant styles on my cat and the one bubba made me is almost identical a the tran. Without it i would slide ,fishtail,slingslot all over the place.


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## Horns23 (Jul 24, 2006)

Melon, did you ever put on the Bob's to see how it worked?


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## curtis provenzano (Jul 15, 2007)

I HAVE A BOATRIGHT, ON A 22VS GULFCOAST. 175 SUSUKI. THEY ARE ON 2351 HEADING INTO FREINDSWOOD. I HAD THEM INSTALL IT FOR EXTRA $40.00. IT TOOK A LOT OF EXTRA GRIDING TO MAKE IT FIT RIGHT. HE TOLD ME THAT IT WOULD BE NO PROBLEM USING IT AS A STEP TO GET INTO THE BOAT. BUILT WELL AND WILL NOT MOVE. THEY ARE WRIGHT, BUY IT AND YOU ARE DONE.


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## Melon (Jun 1, 2004)

Horns23 said:


> Melon, did you ever put on the Bob's to see how it worked?


No I haven't. The one bubba made me is doing the job as of now. I'm still playing with props.lol Trying to tweak this 115. I should not of been such a tight arse and went with a 150.


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## Horns23 (Jul 24, 2006)

I saw a guy with the new 16 Cat w/90 ETec @ POC last weekend. He had tried 7 props and was waiting on 2 more to try. I hope he wasn't buying them all. LOL


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## Shallow_Sport (Jan 22, 2008)

*Shallow Sport plate*

I didn't see any pics of the Shallow Sport one. The one that had the ? on it is not... or at the very least is not the one that they use now. Here is a pic of the SS one on mine. Them main thing I notice that maybe be a hindrance to the the performance of the SS plate is that the actual plate is higher than all the rest of the ones I've seen that run even with the plate on the lower unit. If you look at the pic the SS on is held between the top lip of the lower unit and the top of the anti-vent plate. In one sense it's nice that it has something to hold it from moving around since the front part rests under the lip of the lower unit. But the extra height allows for less "compression" of the water and therefore might allow more air to mix in with water at any particular JP height.

The Manta Ray actually slips over the cav. plate and when looked at from behind runs flush with the plate... which in my mind may allow you to get an extra inch or two of height on the JP without as much ventilating with the SS plate. Not just the mantaray but most others seem to be flush. The only thing is those that are flush have nothing to rest or hold onto on the front part of the lower unit which might allow for flutter and movement which would dig into and damage the lower unit.

Oh, and no, my prop isn't that shiny any more, nor does the lower unit still have all it's paint intact. I never really noticed but from all the debris and sand in the water the leading edge from the compression plate down a couple of inches on the lower unit has no paint and is down to the primer, same goes for the little trim tab, the paints all gone on the leading edge.


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## TexasFlats (Mar 29, 2007)

SS

That's an interesting design on your plate. The picture is playing with my eyes a little bit, but it looks like it might create a lot of turbulence under the plate.

I think that one of the main functions of the plate should be to feed water to the prop from the tunnel. The plates like Bob's and Tran's don't have any way to do that, but I like the curve around the prop that the Tran plate has.

The shape of the end of the tunnel has a lot to do with what kind of plate you need. My tunnel has a big flare right at the end, which creates a lot of spray without a full length plate.










I wish there was a way to combine the curve of the Tran plate with a full length plate.

.


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## Shallow_Sport (Jan 22, 2008)

TexasFlats said:


> SS
> 
> That's an interesting design on your plate. The picture is playing with my eyes a little bit, but it looks like it might create a lot of turbulence under the plate.
> 
> .


I think so too. I don't like the fact that it is not flush to the cav. plate. Manta Ray mfg. is nearby so I've been thinking of dropping the money for it. I really could get away with keeping this one, but I've always liked trying performance things on my cars, why not my boat.

I was thinking... it makes sense that the manta ray is 1/2 thick fiberglass in the front. Since there is nothing to keep it from fluttering around, the mantaray has to be strong enough to keep it's rigidity from it being slipped over the cav plate (the cav. plate slips into a u-channel where you silicone it all together). After thinking of it like that my worries about the front of the mantaray shaking around went away. 1/2 is pretty think and I doubt if I could even bend it at all. I've seen one in person and when you look at it from the back it's perfectly flush front to back and side to side to the cav. plate and that's really what I'm looking for.


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## Baywolf (Feb 13, 2008)

*Texas Flats....*



TexasFlats said:


> SS
> 
> I wish there was a way to combine the curve of the Tran plate with a full length plate.
> 
> .


 TexasFlats, I have one (full length curved), built about three months ago, was tested and performed very well. It looks like an Navy drone plane, and we even made a mold to develope it further, we were gonna take a little drag out of it, and loosen it up, but man you talk about gettin the feeling you just been rear-ended; the back of the boat actually lifts up about 2 inches and then lunges fowarded, not donut, not squat, just "WE ARE GO FOR LAUNCH!" I'll post a pic tommarrow.


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## TexasFlats (Mar 29, 2007)

Baywolf said:


> TexasFlats, I have one (full length curved), built about three months ago, was tested and performed very well. It looks like an Navy drone plane, and we even made a mold to develope it further, we were gonna take a little drag out of it, and loosen it up, but man you talk about gettin the feeling you just been rear-ended; the back of the boat actually lifts up about 2 inches and then lunges fowarded, not donut, not squat, just "WE ARE GO FOR LAUNCH!" I'll post a pic tommarrow.


Now we're talkin'............!!!


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## Shocker (Jul 15, 2005)

Has anyone tried the Shaw Wing? I noticed this weekend that my cav. plate is cracked and needs to be replaced soon before it breaks in two.


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## TexasFlats (Mar 29, 2007)

Baywolf - Any update on your cav plate design?


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## Melon (Jun 1, 2004)

TexasFlats here is the one Bubba sent me after I modified it. Less drag and my hole shot is the same. I even picked up a few more mph of my 115. I took off about 4". Now if they would just add 2 1/2 " to our outboard motors for shinnyboats from the outboard manufactures Id be a happycamper. I hate drilling holes in a perfect good lower unit.lol


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## Melon (Jun 1, 2004)

BTW I need a new driveway!


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## Speckled Horn (Mar 5, 2006)

Jeez Troy, 

Can't you start a thread that doesn't have a thousand post/views? Had fun Saturday helping you hang the motor. You know my vote on the cab plate. Unifit Shallow Blaster. Made a huge difference on my SS with the TRP!

What are you doing? Why aren't you finishing that boat?

Just kidding. Have a great one.


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## Baywolf (Feb 13, 2008)

TexasFlats said:


> Baywolf - Any update on your cav plate design?


Yes, I apologize, it's been a while since i've been able to get back to this thread, I will post a pic as soon as I find the memory card for the nikon.


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## fishnstringer (Oct 20, 2006)

*The ShallowBlaster*

gets my vote. I've had one since '98, and first installed it poorly, due to insufficient instructions from the manufacturer, thus I had wear on my engine's cavitation plate like others. You must use a woodworker's type clamp to draw the sides up against the cavitation plate before installing the fiberglass insert in the rear of the ShallowBlaster, and after you have forced the front of the SB up against the transom of your boat with your trim. I've actually had two, the first one was on a 150 hp engine, and the second one is on a new 200 hp engine purchased this year. The reason I point out that I've had two is to explain the first one was like new when I took it off after almost 10 years! There was absolutely no wear on the unit, including the rubber insert. However, the first one was too small for the new engine, thus it was sold and a new longer one was acquired for the larger engine. Good luck on your choice and enjoy!


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## hotfoot (Mar 22, 2008)

Did'nt figure I needed one on a TRP but the one Joel Euton put on for me on the Ultra Cat has worked very well indeed. Boat stays on plane at 8 mph.


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## gregr1971 (Oct 28, 2005)

here is a good one !


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## TexasFlats (Mar 29, 2007)

Gregr1971-

That's pretty slick. Someone definitely spent some time on that one. From the painted trailer, I'm guessing lake boat - good thing, hate to drag that skeg into a nub after all that work. :biggrin:

TF

.


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## gregr1971 (Oct 28, 2005)

pretty simple mod if you are handy with aluminum welding.


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## Baywolf (Feb 13, 2008)

*Here's a pic, old and broken, but amazing.*

TexasFlats, finally got to where I can get to posting again, here a couple shots of a prototype with a full length tunnel on the cavitation plate. These were "decommisioned" of sorts, either they failed, or they were never finished, but the concept was tested thouroughly, to the point of failure.


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## TexasFlats (Mar 29, 2007)

Baywolf,
Thanks for posting. Didn't get an attachment in your pm recently and haven't been able to reply lately.

Now that I have the motor mounted, I can see a problem:










There is a finger's width of clearance between the front of the lower unit and the tunnel. About 3" from the stock cav plate and the sponson - looks like the Tran style is about all that will fit.

I'm not completely satisfied with anything I have seen so far; some just aren't the right design in my opinion and the others will not physically fit without serious compromises in steering or trim.

Looks like I am going to have to make my own.

Might be fun...

.


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## crabbeater (Feb 9, 2006)

run your boat without one first. by looking at those large sponsons you my not need a cavatation plate.


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## TexasFlats (Mar 29, 2007)

crabbeater said:


> run your boat without one first. by looking at those large sponsons you my not need a cavatation plate.


beater-

I definitely will run it first. However, though it has been a while, I remember how much spray comes out of the tunnel. It's going to need one for sure. I will just need to see it in the water before I will be able to start thinking about my design. I have a few ideas already, but a sea trial will go a long way toward making it just right.

TF

.


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## TexasFlats (Mar 29, 2007)

*Design Considerations Discussion*

I really started this thread to open a conversation on cav plate design rather than just finding one that will fit the boat. As I said in my previous post, I'm just not thrilled about any of the plates on the market right now.

All of the ones that are readily available are slightly different - some designs make sense for certain hulls, and some of them are just a plate over the prop. I may be going toward the deep end by picking this apart, but it seems like so much more could be done with a proper anti-cavitation plate design.

Baywolf has put a lot of thought and work into his plates. Tran has a different approach - one that gets me to thinkin'. Melon has modified his and made it better. This is what I'm after - I'm a detail guy.

Any thoughts on WHY your plate works for you?
Anyone have an idea to make a plate work more efficiently?

TF


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## Shallow_Sport (Jan 22, 2008)

I replaced my Shallow Sport compression plate with this Manta Ray. It's made here in the Rio Grande Valley. All I can say is I'm really impressed. My thoughts as to why this one would work better were right. I think I stated prior in this thread about my thoughts on it.

Like many other plates out there this one is flush with the lower units plate. The Shallow Sport one rides even with the lower unit bolts. In fact if you look closely you can see behind the little exhaust port and anode you can see that there's a line of paint missing, the other side is worse. Forget the paint, it dug in pretty good into the aluminum. It's nice and deep. It wasn't loose or anything but it's design inherently allows for a bit of movement.

Anyway, I felt that the fact that it sits about 1.5-2 inches lower would allow for a higher Jackplate setting while keeping ventilation of the prop down. Since it's lower it's just less prone to allow much air under it when compared to the Shallow Sport one while the Jackplate is at the same height. I ran almost the whole time at 3/4 or more up on the JP and it didn't ventilate at all while running.

Holeshot is better at high JP. Initial holeshot is no ventilation with a tiny bit as I trim out the engine, but it settles down real quick. The SS one was prone to ventilating a lot before it settled down. In many cases I couldn't trim out as high as I wanted. When turning the SS one would loose traction really easilly. With the Manta Ray I've been able to maintain traction at higher turning angles when compared to the SS one.

For some reason the camera does not see the the fact that it's quite a bit wider in the front than in the back. I thought thought it was strange as I saw the pics, but it's about 2 or so inches wider up front.


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## TexasFlats (Mar 29, 2007)

Thanks for posting up the great feedback, SS.

I spoke with the owner of Manta Ray a while back - seems he has put a lot of care into his design and made a solid product. Glad to hear it's working out for you.

I think I'm stuck with building my own - can't seem to find a plate that will clear the key slot on my transom. Should be fun though.

TF


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## Baywolf (Feb 13, 2008)

*Manta Rays*

Is it just me, or have the Manta Rays always had that downward facing skeg/edge tipped inward. Wouldn't it make more sense to tip them out, and gather more water?

TexasFlats, why don't you try and get him to shave off some of the weight, they weigh about 20 pounds, why?


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## Shallow_Sport (Jan 22, 2008)

I double posted the last pic where you can see that the edges tilt in a tiny bit. Even if the angle was a bit different I can't see it making any worthwhile difference. Any angle IMO is good because it helps to "CUP" the water on holeshot and keeping it around the prop with as little air as possible.

The thing I did like about the Shallow sport one is it was perfectly gelcoated on the underside. As you can see in the picture the Manta ray has a unfinished surface on the underside. Again though, I can't see it making any noticeable/worthwhile difference. Anyway, you can't see the bottom while running.

As far as weight I can only imagine it's due to the 1/2 inch thickness toward the front. It's hardcore thick. Overall, it's as thick if not thicker than the SS one at pretty much every point.


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## Tombo (Mar 15, 2005)

I live in Rockport so can some one point me in the direction on closest location for Manta Ray? I have a Majek scooter with the recessed motor mount so space is limited for turning.


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## TexasFlats (Mar 29, 2007)

Tombo,

Manta Ray is down in the valley

http://mantaray1.com/index.html

Give him a call, I think he has some distributors in your area.

TF

.


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## TexasFlats (Mar 29, 2007)

Baywolf said:


> Is it just me, or have the Manta Rays always had that downward facing skeg/edge tipped inward. Wouldn't it make more sense to tip them out, and gather more water?


Baywolf,
I think SS has a point about keeping the water around the prop, but it seems that the hard angle at the back of the plate would create a lot of turbulence when you are trying to jump up out of the hole.

At low speed, like when trying to get up, the water will momentarily flow in a circular pattern around the prop. Once you get underway, the water will flow straight back. Think of it this way - it's like creating a jet drive, which essentially is a prop in an enclosed housing.

Here's my idea on your prototype plate: tilt the wings at the back of the plate down and form a semi-circle around the top half of the prop, like Tran's plate. A smooth, round funnel to feed water to the prop should work in all situations.


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## Friendswoodmatt (Feb 22, 2005)

does anyone run a flats cat with a plate? If so what are you using?


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## fattyflattie (May 20, 2008)

19' Flats cat F115 yamaha boatright cav plate.


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## Shallow_Sport (Jan 22, 2008)

> Baywolf,
> I think SS has a point about keeping the water around the prop, but it seems that the hard angle at the back of the plate would create a lot of turbulence when you are trying to jump up out of the hole.
> 
> At low speed, like when trying to get up, the water will momentarily flow in a circular pattern around the prop. Once you get underway, the water will flow straight back. Think of it this way - it's like creating a jet drive, which essentially is a prop in an enclosed housing.
> ...


I see what you're talking about here. Have the current front part of a plate like the Manta Ray or any other similar, but about halfway back have it transition smootly and have it hug the prop in a semi-circular manner. The only difference between this and trans plate is that this hybrid will actually go from flat to tunnel like. This would cause a lot of upward force on the hybrid plate as it transitions from flat on the front down a bit into a semi-circular tunnel. This could cause some lifting effect at high speeds I'm sure.

Thinking about it though this downward flow in water might be counterproductive since normally the water hits the prop straight on. This downturn in the transition would cause a variance in the way the water is flowing through the prop which could disrupt the dynamics in how the prop is supposed to work. It probably wouldn't even register a bit in top speeds or anything subjective, but it's enough to get you thinking about how the water should flow towards the prop.

I personally don't need any transom lifting effect. I even wish it ran a bit less flat at over 4500 RPM. It drafts so little above 25 mph that it runs with the bow only slightly higher than the back, that there isn't any room for it to run less flat.


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## Baywolf (Feb 13, 2008)

*Tunnel Effect.*

TexasFlats, I agree with the transition you suggest, but it sounds like we are all in agreement that the prop needs this jet like effect. I dont think thats what we intended.
- not for nothing but the prototype was abandoned because it created too much lift, not because it failed to create it. 
I would've liked to reduce the amount of drag from it, but I have moved my focus toward developing the SWA hull, similar concept for lift but also adaptable to a jet drive propulsion unit, (help save the beds). I figure if you design a boat to capitalize on the lifting characteristics that water inherantly wants to provide, you won't need a cav plate; you could take the "hole" portion of "holeshot" and through it out the window. Imagine getting on the boat and instead of tucking in the prop or turning down the trim tabs, or doing donuts, you simply only have to worry about whether or not the four to five inches the boat is drafting will atleast go on for the next boat length so you can get on plane. (and I don't mean a skooter, a jon boat, or poling rig, I mean a big 21' to 25' honest to goodness four fat guys and cooler full of fish boat.)
I hope this didn't come out in a bad way, but props are kind of primative, alot like wooden wheels on buggies, we shouldn't keep asking about cavitation plates, we should ask about the which boat designs have truly changed how we can fish the shallows.


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## Iam74Gibson (Aug 11, 2005)

*Bobs Machine Plate?*

After reading this thread and seeing there are a few brands out there that may be good, I would like to ask if anyine has had experience with the Bob's machine plate...*True Tracker (Stabilizer Plate)*

*








* 
The reason I ask is, in about a week or so, I will be sending the lower unit of my 150 H.O. Etec to them to have a low water "Bigfoot" nosecone installed. This will include painting it. I am thinking that since this plate only cost $59, it may be a good idea to have them install it and paint it all together. So any feedback is appreciated.


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## FLATSDADDY (Mar 25, 2008)

I had a Mantaray installed on my boat a couple of weeks ago. I have not had a chance to test and see how it will perform. I replaced the one that came with my boat originally as it was causing wear on my lower unit due to bibration. It looked like a SS design. 
The mantaray, I was told, has not been installed on a cat design before. I'll be the science project and I am hoping for equal or better performance than I had; minus the lower unit wear.
Will post and share info with you folks. Good or bad.


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## TexasFlats (Mar 29, 2007)

Iam74Gibson said:


> After reading this thread and seeing there are a few brands out there that may be good, I would like to ask if anyine has had experience with the Bob's machine plate...*True Tracker (Stabilizer Plate)*
> The reason I ask is, in about a week or so, I will be sending the lower unit of my 150 H.O. Etec to them to have a low water "Bigfoot" nosecone installed. This will include painting it. I am thinking that since this plate only cost $59, it may be a good idea to have them install it and paint it all together. So any feedback is appreciated.


Gibson,
Sounds like a good plan - you're going to love the nosecone. Painting it all the same will look nice. What hull are you putting this on?

TF

.


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## Baywolf (Feb 13, 2008)

*Acadamy*

I saw a neat little plate on the shelf at Acadamy, it was semi-circular, and sort of expanded on the hydrofoil principles. Cost was $149, I didnt care much for it, but I think the basic idea of the roundness with the prop looked good.


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## TexasFlats (Mar 29, 2007)

FLATSDADDY said:


> I had a Mantaray installed on my boat a couple of weeks ago. I have not had a chance to test and see how it will perform. I replaced the one that came with my boat originally as it was causing wear on my lower unit due to bibration. It looked like a SS design.
> The mantaray, I was told, has not been installed on a cat design before. I'll be the science project and I am hoping for equal or better performance than I had; minus the lower unit wear.
> Will post and share info with you folks. Good or bad.


Looking forward to your reports on how it works. Seems like a well built plate. Will be interesting to see how it does on a cat.


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## Horns23 (Jul 24, 2006)

I have the 19 Shoalwater Cat w/150 Etec. I had the Shallowsport design on my boat but wasn't too crazy about it. I tried running without it but the only way to keep it from porpoising on smooth water was to trim it way down. This also put alot of drag on the boat and wasn't very fuel efficient. I was at Bass Pro Shops the other day and saw a SE Sport 300 design. It looks alot like the one Melon put on his boat except it is a hard plastic instead of fiberglass. I think it was like 60.00. They have one for small motors and up to 300 HP. They have them in white or black, sorry no gray. LOL I decided to give it a try since the SS was eating into the motor. The results were great. I went to Matty Sunday to try it out. First thing I noticed was how much quieter the motor was. Then the fog was so thick you couldn't see 75 yards. I was able put it on plane at less than 20 MPH. This made it nice not having to plow down the Intercoastal. Once the fog lifted I was able to test it out. I ran it in smooth water and was able to get 5600 RPM for the first time since I bought it. It ran 51 MPH and I was able to raise the trim all the way to the middle line without porpoising and very stable. I was running the jackplate on 3.5 and never changed it. I ran it in a light to medium chop later in the day and still ran it 48 MPH. On holeshots it felt like the bow never came up, just took off. If any of you guys are looking to replace the SS design you need to give this plate a look. I was very pleased with the results and would highly recommend it.


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## ATE_UP_FISHERMAN (Jun 25, 2004)

Nedski works the best on my cat. It's a world of difference in the bow control and shallow water performance. You will love it.
*Nedski Marine Svc*

611 Pine Cir
*Seabrook*
*TX*
77586-1920

281-474-5640 Phone


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## Blown2run (Jun 22, 2006)

On my previous boat, I installed Dargel's compression plate and I guess it worked alright. Didn't have anything to compare it with. For my new/used boat, I was considering the Shallowblaster but thought it was a bit pricey. So I decided on the Manta Ray at $204.52. Just bought it about 30 minutes ago. Called the number on the website and the owner answered, Roland. He agreed to bring it to me himself. Now that's customer service. Upon inspection, this Manta Ray is well built and tough. At least twice as thick as Dargel's. Will post once I try it on the water.


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## Iam74Gibson (Aug 11, 2005)

*Bobs Machine Plate*



TexasFlats said:


> Gibson,
> Sounds like a good plan - you're going to love the nosecone. Painting it all the same will look nice. What hull are you putting this on?
> 
> TF
> ...


Hi TF, I have a 2007 Bluewave 190 deluxe with a Bob's 6" jackplate....

After the nosecone, is an 8 ft powerpole, then I am ready for spring!!


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## redfishrt (Feb 25, 2009)

I have been following the thread and noticed Texas Flats hasn't posted in a while...did you make a decision? Are you gonna build your own? I ask because I recently built my own design...Let us know where you stand...


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## wolffman (Jan 7, 2005)

*Nedski 100%*

go see Ned - he will custon build exactly what your boat needs. I am on number 5 and Nedski cannot be matched!


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## hardcore (May 31, 2005)

i would go for the design with the least drag, cuz u got alot of sponson surface area to keep it from squatting already.


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## marty benge (Aug 20, 2008)

proper installation I always silicone all edges and gaps let it set up a couple of days yes slimshady is right. get it tightpushing plate back for snug fit and useing ratchet strap then put spacer in cut to fit use 4 bolts and silicone.I also silicone the grooves in the shallow blaster before putting on. Also cut hole in rubber to change gear lube without plate removal.Full plates work well on tunnels whale tails on others. mine was built by ultra cat and well. good luck marty


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## TexasFlats (Mar 29, 2007)

redfishrt said:


> I have been following the thread and noticed Texas Flats hasn't posted in a while...did you make a decision? Are you gonna build your own? I ask because I recently built my own design...Let us know where you stand...


rt,
Pretty sure I'm going to build my own. I had a Nedski on the old motor and it may be easier to just let Ned take care of it for me, but I have a couple of ideas I may want to try out. The boat gets up pretty good, even without one - so the pressure is off for now. I will definitely need it when I start making regular trips to POC.

How did your design work out? Did you build a mold? Pics?

TF

.


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## FLATSDADDY (Mar 25, 2008)

Got a Mantaray Cav. plate installed on my Shoalwater 21 Cat a couple months ago. The plate does as intended/promised. It e;iminates blowout dramatically. Even with raised with half the prop out of water, there is no rooster tail or blow out. Even the wake looks different while on plane. The back of boat seems to run a bit higher out of water and I also noted a slight increased of porposing which is easily corrected by adding a few degrees of trim. 
Top end is slightly 3-4 mph lower if running with the back of boat slightly higher than before as the prop is higher in the water. Overall the Mantaray is an effective, solid performer. It also looks pretty well finished out and even looks factory original equipment. Roland was a nice guy to deal with and even installed the plate for me at his driveway(no charge). I would recommend the plate/buying/customer service experience with Mantaray. I hope it helps other people on the fence looking at cav. plates.


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## talkshow (Aug 11, 2006)

anyone use a Davis whale tail xl?????????


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## redfishrt (Feb 25, 2009)

TexasFlats said:


> rt,
> Pretty sure I'm going to build my own. I had a Nedski on the old motor and it may be easier to just let Ned take care of it for me, but I have a couple of ideas I may want to try out. The boat gets up pretty good, even without one - so the pressure is off for now. I will definitely need it when I start making regular trips to POC.
> 
> How did your design work out? Did you build a mold? Pics?
> ...


TF,
I built my own design based on the shallow blaster/shaw wing and others I have seen. I started with a cardboard template, then made a fiberglass mold. This was a time-consuming process, but I would say it only cost around $50.00 in supplies. Not bad compared to the plates in the $250 range. The obvious advantage is using exact dimensions that fit your motor perfectly.

One of the main functions of a plate that it seems ppl overlook is how the plates are designed to gather water from the front of the motor. Prior to the cav plate install, the water hitting the front of the motor would be deflected upward (creating a "V") of water up and away from the prop. The plates that have full coverage then, in my opinion, are the most effective in gathering in this water. I feel that the "tail" designs and even the tran style plates fail to collect this water I am talking about. See pics on how my design worked out. Since I have an older motor (1999) I wasn't concerned with a few holes drilled in the motor, so you can see the bolt-on installation. A few of the design details I used: slight scoop up in the front of the plate, small side fins along middle of the plate.


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## goodbull76 (Apr 26, 2008)

Is the Boatright Cav plate everyone is talking about the one in Friendswood? Any idea on cost? Thanks!


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## TexasFlats (Mar 29, 2007)

goodbull76 said:


> Is the Boatright Cav plate everyone is talking about the one in Friendswood? Any idea on cost? Thanks!


http://www.boatrightmarine.com/contact.html

Looks like Webster, although there are some dealers who sell their plates. It should be 250-285 plus installation.
Let us know how it works out for you.

TF

.


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## Sponge (Jun 22, 2004)

*Manta Ray*

I have tried the Manta Ray and the SS one. Hands down the Manta Ray is better but now i'm running the SS. Only reason is that my Manta Ray cracked on the front end because I listened to my mechanic. He said it was a pain in the arse to take off when having to replace the lower unit oil. The plate was in the way of the upper screw. He told me he was very positive it would not come off if I only used very little RTV. Well I listened to him and it popped off the lip of the motor plate and cracked. Since I had a spare SS I put it on. What a difference. The Manta Ray is much better. Probably going to make a change back to MR but I need to see if I can drill a hole so that I can get to the upper lower unit screw to change out my oil in the future without having to pull off the plate.



TexasFlats said:


> Looking forward to your reports on how it works. Seems like a well built plate. Will be interesting to see how it does on a cat.


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## TexasFlats (Mar 29, 2007)

Thanks for the report, Sponge. The back-to-back comparison between the two different plates is good feedback. I have heard a lot of good things about the Manta Ray. I bet Roland can help you out with the access hole for the lower unit oil.


TF


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## Sponge (Jun 22, 2004)

Yeah I talked to him today. He's going to hook me up with a new one once I send him the old one. Roland stands behind his product. 

Sponge


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## Shallow Sport68 (Oct 14, 2008)

How about the ones from Shoalwater? they seem to work pretty good.I wonder what they sell them for?


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## knowphish (Jul 10, 2008)

I run a Bob's on my Action Craft. That being said, it works great for the pocket tunnel on my A/C. If you have a full tunnel you might find Bob's a little on the small side. I just saying it's quite a bit smaller than all the other cav plates.


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## Blown2run (Jun 22, 2006)

Sponge said:


> I have tried the Manta Ray and the SS one. Hands down the Manta Ray is better but now i'm running the SS. Only reason is that my Manta Ray cracked on the front end because I listened to my mechanic. He said it was a pain in the arse to take off when having to replace the lower unit oil. The plate was in the way of the upper screw. He told me he was very positive it would not come off if I only used very little RTV. Well I listened to him and it popped off the lip of the motor plate and cracked. Since I had a spare SS I put it on. What a difference. The Manta Ray is much better. Probably going to make a change back to MR but I need to see if I can drill a hole so that I can get to the upper lower unit screw to change out my oil in the future without having to pull off the plate.


I second. I recommend cutting around the zinc anode on the rear which holds the lower unit bolt. I did so after I needed to access it to change the water pump. Manta Ray is a tough, tough, SOB and works awesome. Roland's customer service is second to none. Good luck.


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## NautiGirl (Feb 16, 2006)

I ended up siliconing a Black Manata Ray on a 150 Mercury. The plate works great, looks good, and was an easy install.

Good Luck!


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## Durtjunkee (Mar 23, 2007)

NautiGirl said:


> I ended up siliconing a Black Manata Ray on a 150 Mercury. The plate works great, looks good, and was an easy install.
> 
> Good Luck!


did the same thing on my 200 yamaha. looks good and does its job but it took away some of my top end speed and it worked loose after a couple of months. took it off and am going without this weekend to make a comparison. may or may not re-install it.


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## fishsmart (Dec 5, 2004)

As far as I know, there is no performance data or plate to plate operating data so you can determine performance advantages that might exist for any brand. 

It quickly gets down to which one looks the best or bolts on with the least damage, etc... or just buy on price.

Wish we could buy based upon documented and measureable guaranteed performance.

Charles


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## TexasFlats (Mar 29, 2007)

fishsmart said:


> As far as I know, there is no performance data or plate to plate operating data so you can determine performance advantages that might exist for any brand.
> 
> It quickly gets down to which one looks the best or bolts on with the least damage, etc... or just buy on price.
> 
> ...


I agree - but what an undertaking that would be!

How many different hull / motor combinations are there? Add in different props, load, water conditions, trim tabs, etc,....

Would be nice to have a shootout with at least a couple of popular hull / motor combos. Anyone want to "donate" their motor to the cause - a couple of extra holes won't hurt at all :wink:

TF

.


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## Tonysend2001 (Apr 22, 2005)

I had a shallow blaster on my 23ft mod,tunnleV. It function well but just about destroyed the lower unit housing due to moving and vibrations and acted like a grinder.. I attempted to have a nedski put on but he refused due to the damage that was done from the shallowblaser. And drilling would prob have caused more problems. I ended up buying a Shawing and have had it on for about a year and works great, And does not shake,move, or vibrate at all. and covers up the damage left from the shallowblaster. I am not sure for your application but you can call fibertex at 361-991-5956 and ask them. Also you cause no damage when installing the shawwing. No need to drill into your housing.


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