Trim Tabs vs. Interceptors

I have run several fast boats with interceptors like the 45' Hatteras EX and they work very well. I am running a new 52' Manhattan at 20 knots and they work fairly well, BUT I think tabs may give more stern lift. If you're running tabs full down, sounds like you may be a bit undertabbed…….now with the new engines and lighter weight and new prop design, I would be inclined to run the boat as is, see how it performs and then change them next haulout if necessary.

I "have" a set of Interceptors completed, but waiting to get on a plane from AUS for our Cat C12 715hp powered Tiara 42 Open. The original MI props had some cav burn when I bought the boat used that we've been chasing so finally decided it was time to replace... With the current setup, we were running 28.5-29kts @ 75-80% load, burning 50-52 gal/hr with maybe 30% tab. Once they finally arrive and we're able to splash the boat to test, I'll post our findings.

Max

Apologize for the confusion... I was talking about Veem Interceptor propellers not interceptor tab system. We still have the stock Bennett tabs on the boat.

max

I have to agree with J , run with the tabs you have now first to see how the weight change affects everything, the reduction in weight may slightly shift your CG forward and up resulting in a flatter running trim and maybe , hopefully, less than full tab required.

Trim tabs that extend beyond the transom as opposed to being set into a hull pocket are amplifiers of a following/quartering sea. I like the design of the Interceptor.

I think traditional tabs provide more stern lift on the slower boats that need help (more stern surface area) to stay on plane. On faster boats that solidly stay on plane without the use of tabs, and the tabs just add more speed and better running attitude, the interceptors help and they do a good job at stabilizing the boat. Traditional tabs seem to do a better job at correcting list, on boats that routinely list when on plane (FB MY's mainly). It really depends on the hull design, type of boat, and mainly the cruising speed. 30 knots and above the interceptors are the clear winner, below that it really just depends on the above mentioned factors.

While Lazzara's tend to run pretty flat and this works, I'd prefer interceptors as you can go with 0 and raise the bow a bit, or put the tabs down further at slower speeds to stay on plane or in rough seas. I prefer to have some adjustment to the running angle.

Wow. My 53c had the pocketed version, and were very rarely used. Had I thought of extending the running surface as you did, I might have given some considerable thought to that...

...I did, however, like them tucked in with the pocket versions when fishing in deep water, not protruding, be it for fish, lines, or wave action.