bertram31.com

Hey guys, I’ve red quite a few posts on trim tabs on the 31. From what gather they may be beneficial to slow speed cruising? My 1970 Bahi Mar has low horsepower engines (Perkins 185hp) I cruise at 16kts fully loaded. I’ve been running the boat with no tabs for the last 3 seasons and never had a need to adjust due to weight with coolers and ice and passengers. I’m I missing out on getting better low speed cruising without tabs? Going to be hauling out for the season soon and was thinking of maybe doing an off-season project. What do you all think? Thanks

My experience is this: Having trim tabs changes the angle of attack at planing speeds just slightly and improves the ride. I almost NEVER adjust the trim tabs. I like the benefit. As for the actual Bennett Trim Tabs, they are a corrosion headache no matter how good I keep the zincs. One of the few times I adjusted them due to wind so one was up and the other down, the down trim tab ripped off and now sleeps with the fishes.

I just added my trim tabs to the bonding system, so we'll see.

If I had it to do over again, I think I would have non-moveable trim tabs fabricated from a heavier gauge steel.

Good luck.

Chris,

I had Chrylser 440's and now Cummins 210's. I'm not much faster and I can almost always add at least 1mph more speed by adding some tab. I also like bringing the nose down a bit for a better ride, better visibility and sometimes it will run a bit drier.
Does the boat need tabs? Nope, I ran for a good 10 years before I put them on.

In your lower hp application you'll definitely benefit from the lift in the arse end that the tabs will give you right through your rpm spectrum.
Money well spent!
Good luck.
John

the only time i use my tabs is when i want to go faster in the no wake zone if i put them all the way down i put out much lower wake