There are two situations in particular where the trim tabs need to be used:

• When it is desirable to trim the bow down in a rising sea and at speeds between going up planing and cruising speed.

• When running with a strong beam wind.

A planing boat always leans into a strong side wind. This reduces the boat’s seakeeping qualities, which is why listing to one side needs to be eliminated as far as possible. Lowering the trim tab on the windward side brings the boat back into normal attitude.

For trimming the bow down, both trim tabs are used in parallel. Begin by retracting both trim tabs completely, then lower both of them a little at a time, so that you retain complete control over how the boat is affected. When running with a following sea, both trim tabs always need to be fully raised. The reason for this is that boats have a tendency to “dive” in a strong following sea, which can result in uncontrollable slowing. Therefore you must run the boat with a high bow angle in a following sea.