Hydrofoil pros or any cons ?

Blueone

Well-Known Member
SILVER Sponsor
Jan 24, 2007
13,688
Lake Erie, Ohio
Boat Info
2004 420 Sundancer
Engines
Cummins 6CTA 450's
I keep running into people with various hydrofoils on their dinghies outboard that are really happy with them.
I have a 10’ soft bottom with a 9.9hp and it will cavitate once in a while when on plane. I have played with trim but just makes it worse. Supposedly the hydrofoil will help.
Question is will drilling holes in your outboard and spending $100 be worth it ?

this is what I am looking at…is there something better out there?

https://www.permatrims.com/M6_Black_Permatrim_Hydrofoil_p/m6_blackmercury4stroke.htm

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Blue,

just put an SE 200 with the sport clip on my 25 hp Tonhatsu on a 12’ rib. Get up on plane easily. Sport clip works without drilling into your motor. https://sesport.com/
 
Blue,

just put an SE 200 with the sport clip on my 25 hp Tonhatsu on a 12’ rib. Get up on plane easily. Sport clip works without drilling into your motor. https://sesport.com/
Geez…they couldn’t make that more complicated to not drill a hole…. Just watched an installation video
 
It’s not that bad really. Took about 45 minutes from start to finish.
 
I have the same. I see 'em all over these days so they must be doing something right? I can't compare before/after but my slightly obese 325 tender does well with it. 2 adults, 3 kids and a 70lb dog planes fine. With four full size adults she can struggle still...

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Blue, what you're probably experiencing is ventilation, not cavitation. Cavitation deals with imperfections with the prop and the creation of tiny air bubbles that then pop and slowly damage the prop. Ventilation is a little more straight forward and that plate above the prop is called the anti-ventilation plate - although, for some reason, is quite common for the plate to, wrongly, be referred to as an anti-cavitation plate... even by some manufacturers!

Are you able to lower the engine any further? Even an inch might solve the problem since ventilation happens when the prop gets too close the surface. The plate helps under normal conditions, but not if the engine is too high. Do you only have V when turning - or also during some straight runs? Bouncy conditions can of course make it happen more readily.

OK, that was a long winded response and not really on topic to your question :) Whether or not the plates can help is sort of a hit or miss thing. You never really know till you try. Sometimes they help, sometimes they make it worse. Some of them are designed like an upside down airplane wing to help lift the stern to get on plane faster, too.

But, no, from my experience, having holes in the anti-V plate will not cause any issues if it turns out to make things worse for you. I have holes in a small engine and a big engine - if there's any performance issues, I can't tell.
 
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I also use the same SE 200, but bolted on. I have used these on every dingy engine I have had. So much so my last purchase, last August of a 15hp Yamaha, I automatically ordered a new SE 200. There's more benefit then anti-cavitation/ventilation, it also helps keep you on plane at slower speeds as well as getting you on plane much quicker. The only thing I do different from their installation is put the bolts in from the water side, I feel it's less disruption of water flow with the rounded bolt head on the bottom opposed to the bolt and nut extending into the running water surface.

I wouldn't thing twice about using one, you will love it.
 
I also use the same SE 200, but bolted on. I have used these on every dingy engine I have had. So much so my last purchase, last August of a 15hp Yamaha, I automatically ordered a new SE 200. There's more benefit then anti-cavitation/ventilation, it also helps keep you on plane at slower speeds as well as getting you on plane much quicker. The only thing I do different from their installation is put the bolts in from the water side, I feel it's less disruption of water flow with the rounded bolt head on the bottom opposed to the bolt and nut extending into the running water surface.

I wouldn't thing twice about using one, you will love it.
The SE200 just delivered to the house…will give it a try this weekend.
 
The SE200 just delivered to the house…will give it a try this weekend.

Looking forward to hearing the results. My neighbor put one on his 60hp that powers his Boston Whaler and swears by it.
 
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I have a full width fin that bolts on the lower unit of my 50hp on the dinghy. It came that way when I bought it - so can't compare with or without.

The dealer said I would want it. I think it definitely helps getting the bow down at lower speeds. I would do it again.
 
Just curious, if these aftermarket tabs are so great, why don't the OEM's just build their motors with larger plates to start with?
 
A bit late to respond, but I put Maxi Marine lifter tabs on my Mercury 310 with 8hp Yamaha. Before it would bow in the air on take off and to keep it down meant trimming it in too much and then it plowed nose down on plane. Solved both problems. Makes backing it up a bit of a pain though. The lifters are easily removable too. Here is a youtube video I did soon after I bought them showing how they work.
 
I have a 310 Zodiac aero with a new 9.9hp Mercury. I ventilated (@Lazy Daze) all the time at the lowest trim. The trim has three settings 1,2 and 3. Installed the SE200 and the nose plowed at the first setting no speed but planed, setting two was the best. I am losing some top end but no ventilation… setting 3 and ventilation was back but so was top end speed. So you lose a bit of speed but on setting 2 no ventilation.
Ran around for 4 hours this afternoon, beached at the sandbar in Sandusky bay…. Great afternoon !

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The water temps must be really warm on Erie considering its 82 degrees in southern Georgian Bay the past couple of weeks.
 
I have a 310 Zodiac aero with a new 9.9hp Mercury. I ventilated all the time at the lowest trim. The trim has three settings 1,2 and 3. Installed the SE200 and the nose plowed at the first setting no speed but planed, setting two was the best. I am losing some top end but no ventilation… setting 3 and ventilation was back but so was top end speed. So you lose a bit of speed but on setting 2 no ventilation.
Ran around for 4 hours this afternoon, beached at the sandbar in Sandusky bay…. Great afternoon !

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Good to hear the performance improvements. How'd the install go? Mine arrived Friday as we were walking out the door so it hasn't gone on yet. The 15hp really wakes this dink up... to choppy out for any WOT runs though.

@Creekwood I meant to turn my chartplotter on when we got back to the boat to check the temp, easily over 80° on southern Lake Michigan today.
 
Good to hear the performance improvements. How'd the install go?
Watch videos 1 and 2 ….reading words from the sheet sucks. I attempted fastening the stainless tether to the Zinc….then quickly said screw this…. If the thing is going to come off then my fault for buying a $50 plastic clamp… rest of it was easy….even in 90 degree heat
 
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I picked up the SE 200 last week and installed on my 15hp EFI Suzuki. On a 9' Achilles rib, 15hp is above the max hp rating for the boat. It would get on plane in the past, but we would usually need passengers to sit near the front. Now with the hydrofoil it pops right up, regardless of where people are seated.
 
I picked up the SE 200 last week and installed on my 15hp EFI Suzuki. On a 9' Achilles rib, 15hp is above the max hp rating for the boat. It would get on plane in the past, but we would usually need passengers to sit near the front. Now with the hydrofoil it pops right up, regardless of where people are seated.

Any vibrations from it? I put it on my 15hp Suzuki on Saturday (one of the rubber washers is now in davey jones locker)...and getting a vibration at around 2500rpms from the motor. Wasn't going to run out to the hardware store for just that...so I'll put the missing one on this weekend. Thought about pulling it off the motor and trying it without...but a drink was calling my name LOL.

She does seem to run better and faster...after I played with the trim settings a bit. Think I left it at the 2nd or 3rd from the bottom (with my 10' Newport Vessels air floor).

@Blueone - any noticeable vibrations from the motor since you added yours?
 
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