Off With the Trim Tabs

OK. I put this in the category of failed experiments. I am sure trim tabs are great, but not on this dinghy. I think the problem is that they are too close to the tubes and outboard. Not enough room on the little transom.

Here is the original post about the installation.

We were at Roche Harbor on the guest dock with the boat facing the right way. The sun was shining, so I took advantage of the opportunity and pulled them off. And nothing fell in the water – including me.

The dinghy is much more fun now. Woohoo!

4 thoughts on “Off With the Trim Tabs

  1. Do you think having a foil on the outboard and trim tabs too somehow created a cancelling effect? I noticed your tabs trimmed down, also. I purchased a competing brand but have yet to install them. Now I am hesitant. First time reader of your blog, which is surprising, as it took so long to come across it. I follow a few other blogs: Slowboat, Windbourne, and Riveted, and Sail Life on YouTube. I and have been a sailor since 2012 aboard Sandra Marie, a 1996 Jeanneau Sun Odyssey currently docked in Bremerton. Nice writing and photos!

    • Hi. Kevin. Thanks for the comment. I think the problem was that the transom is not very wide. The tubes of the inflatable extend back about sixteen inches. The trim tabs had to fit between the tubes and the motor. There is just not much room there. The trim tabs we used are just a spring inside of a housing so they are all the way down unless water pressure pushes them up when the dinghy is at speed. When the dinghy is at speed, the trim tabs, along with the keel of the boat, create a big hole in the water for the motor and the hydrofoil. There was just too much stuff back there. I think the hydrofoil was all that I needed. With the trim tabs, I could get to plane about 10-11 knots. Top speed was about 19 knots. Without the trim tabs, plane is at 12-14 knots and top speed is 22-23.

    • That’s a part of it. The boat was 4-5 knots slower. Although they are intended for 10-14′ boats (ours is almost 12′), I don’t think they mean inflatable boats. There isn’t much room on our transom. The outboard has a hydrofoil on it. At speed, the trim tabs created a big hole in the water. That’s where the outboard and hydrofoil ran. All in all, the trim tabs negatively impacted performance on our little dinghy.

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