Are trims tabs worth it?

[spareparts]

they haven't been out long, I've seen them on larger boats. Personally I don't think the will work as well as afterplane type(bennett, Lenco, etc) on smaller boats for planing off. While on plane, they seem to work very nice, and seem to better suited for attitude and leveling controll rather than planing performance. Knowng they are made by Volvo, they can't be cheap.