Putting trim tabs on dinghy

[Colin A]

I have used the nauticus smart tabs before on RIBS. they work reasonably well.
Nauticus Trim Tabs | Smart Tabs

Seems the Bennett is similar. You may want to see about pitching down your prop as well may help, but watch for overrevving.

[MV Wanderlust]

Originally Posted by Colin A

I have used the nauticus smart tabs before on RIBS. they work reasonably well.
Nauticus Trim Tabs | Smart Tabs

Seems the Bennett is similar. You may want to see about pitching down your prop as well may help, but watch for overrevving.

Appreciate the info, Colin. Thanks.

Already had an outboard shop adjust the prop pitch. That didn't fix it. Adding fixed or self-leveling tabs was pretty much my last resort. Love the dinghy so don't want to get rid of it.

[Colin A]

Originally Posted by JohnEasley

Appreciate the info, Colin. Thanks.

Already had an outboard shop adjust the prop pitch. That didn't fix it. Adding fixed or self-leveling tabs was pretty much my last resort. Love the dinghy so don't want to get rid of it.

Sometimes with a short boat there is no way around shifting weight around but tabs do help. If you look at short Ribs like Zodiac Yacht line they have running surface aft the transom. Novurania actually uses the smart tabs for the same reason.
2017 Novurania 400 DL for sale
https://www.zodiac-nautic.com/en-us/...yachtline-340/

Back when 2 stroke motors were the thing you could kind of getaway with it when but with a 4stroke aft the transom and under 13' long you often need a boost.

[Fence Man]

This is a 12' boat that I built. We tried it without pods, and it wouldn't go anywhere. I ditched the surface drive for a 50 horse Mercury 4 stroke, and it'd go, but would porpoise so bad you couldn't hold on at about 20mph. I bent the trim tabs on the pods that I built for it down just a little more (see photo) and just like magic, it'd run 45. As stated before, short boats are weight sensitive, but in my experience, trim tabs wouldn't hurt a thing. Good luck with your modifications.

[MV Wanderlust]

How would adding such tabs affect the handling in reverse? We really don't back up much... mostly just when pulling away from a dock or swim platform or boat ramp... and always at idle speed.

[MV Wanderlust]

Originally Posted by Fence Man

Attachment 155040

This is a 12' boat that I built. We tried it without pods, and it wouldn't go anywhere. I ditched the surface drive for a 50 horse Mercury 4 stroke, and it'd go, but would porpoise so bad you couldn't hold on at about 20mph. I bent the trim tabs on the pods that I built for it down just a little more (see photo) and just like magic, it'd run 45. As stated before, short boats are weight sensitive, but in my experience, trim tabs wouldn't hurt a thing. Good luck with your modifications.

That's pretty cool, Fence Man.

[SV Bacchus]

Originally Posted by JohnEasley

How would adding such tabs affect the handling in reverse? We really don't back up much... mostly just when pulling away from a dock or swim platform or boat ramp... and always at idle speed.

No expert here but I think if you back fast it may pile up more water on the face of the transom. If you back like a sane person I doubt you would even notice the difference.

Completely different boat but on a 30' Proline, with the tabs level with the bottom, no difference noticed.

[Blaine]

Agree with all that's been said. You didn't mention where your fuel tank is. If it's not already at the bow, try getting a tank made to fit there. Any weight you can move forward will help you get on plane. I made a plywood base for my tank and added a couple of eyelets so I could strap it down. Not a perfect solution but it did help.

[MV Wanderlust]

Originally Posted by Blaine

Agree with all that's been said. You didn't mention where your fuel tank is. If it's not already at the bow, try getting a tank made to fit there. Any weight you can move forward will help you get on plane. I made a plywood base for my tank and added a couple of eyelets so I could strap it down. Not a perfect solution but it did help.

You're right, Blaine. I did forget to mention that. The fuel tank is under the deck as far forward as it can be.

[HopCar]

I've actually been thinking of replacing the trim tabs with sealed boxes. The bottoms of the boxes would give me the surface area I need aft and the boxes would add floatation.

I could use the extra floatation because I think the engine is heavier than the boat was designed for. If I'm not careful when I come down off a plane, the stern wave can come over the transom. Two 1/4 cubic foot boxes would add about thirty pounds of floatation.

[otterhound]

Make sure your motor isn't mounted too low. The ventilation plate (lowest plate) should be even or slightly above the lowest point of the bottom. This can make a big difference in how the boat gets up on a plane. The further the prop is below the surface the bigger the hole it digs especially on shorter boats. You should be able to see the ventilation plate either on top of the surface of the water or very close to it when on a plane.
Rod

[Herb Miller]

How would adding such tabs affect the handling in reverse? We really don't back up much... mostly just when pulling away from a dock or swim platform or boat ramp... and always at idle speed.


Maybe you could mount the tabs on hinges that allow the tabs to lift up when in reverse, but are engaged when moving forward.

[HopCar]

Originally Posted by Herb Miller

How would adding such tabs affect the handling in reverse? We really don't back up much... mostly just when pulling away from a dock or swim platform or boat ramp... and always at idle speed.


Maybe you could mount the tabs on hinges that allow the tabs to lift up when in reverse, but are engaged when moving forward.

The tabs on my Skiff have no noticeable affect in reverse.

[Cheechako]

That's a lot of weight for a small boat. Too much for 15HP. My 10 ft RIB was half that weight including the 15 hp engine. No problem. You're putting lipstik on a pig. Get 25 HP or a lighter boat is my advice.
From the picture, with the console weight forward and the engine/transom so far forward, it's really surprising you need to get the bow down. It appears you have the room inside the boat of an 8 footer with that transom way up there.