# Cavitation plate on 25 hp evenrude on SC 18



## Icroc (Feb 23, 2013)

I know I need a 4 bladed prop, but I think I also need a cavitation plate. 

Has anyone used this cavitation plate from Cabelas on a tunnel hull?

*SE Sport 200 Hydrofoil*









*SE Sport 200 Hydrofoil*


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## swaddict (Dec 19, 2009)

IMHO, cavitation plate is the last item to get with a tunnel hull. They work in very specific situations. My order would be 4 blade prop that is matched to the correct rpms of my motor, next would be trim tabs, then a jack plate (to fully utilize the tunnel hull and your 4 blade prop), if jack plate is not an option then test different mounting locations of the motor and finally a cavitation plate if your are still 'blowing out"


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## el9surf (Dec 23, 2008)

With the height of the transom and tunnel on the sc18 I don't think a jack plate is necessary. I guess you could mount it so you could lower the motor down below where it would normally sit if mounted on the transom. 

4 blade cupped prop is going to help more than a jack plate.


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## Sublime (Oct 9, 2015)

I have a cavitation plate on my Glades X tunnel with a 30 etec. Like a dummy, I didnt' run it without first to see what it would do. I'm going to take it off next opportunity and just try it. I think my plate and any plate is going to cause some drag and scrub some speed off. When I'm jacked up all the way, the plate is pretty much high and dry so it can't be doing me that much good other than at slower speeds.

As far as tabs, they make a HUGE difference on my boat. Trim the bow down and holy cow the tunnel really fills up with water. It is extremely noticeable.


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## No Bait / Lures Only (Apr 10, 2011)

Sublime said:


> I have a cavitation plate on my Glades X tunnel with a 30 etec. Like a dummy, I didnt' run it without first to see what it would do. I'm going to take it off next opportunity and just try it. I think my plate and any plate is going to cause some drag and scrub some speed off. When I'm jacked up all the way, the plate is pretty much high and dry so it can't be doing me that much good other than at slower speeds.
> 
> As far as tabs, they make a HUGE difference on my boat. Trim the bow down and holy cow the tunnel really fills up with water. It is extremely noticeable.


Does the plate assist in keeping water to the motor ?


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## Sublime (Oct 9, 2015)

stephenchurch said:


> Does the plate assist in keeping water to the motor ?



Sorry, just now answering. There is no way to run a water pressure gauge on the 25 and 30 etecs. I never ran it without it which I am planning on doing Friday. All I can do is look back and make sure I have water coming out of my tell tale which I do no matter how high I am running the motor.


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