Trim: When And How To Use It..
Power Trim
Start the boat's motor and proceed at idle speed to a location where it's safe and legal to power up the boat.
Use the "trim down" button (typically located on the handle of the throttle/shift lever) to trim the motor to the fully down position. With the motor at idle, you can usually hear the whine of the hydraulic motor change when the fully down position is reached. Many boats come with a trim indicator gauge on the dashboard with a needle that moves up or down relative to the trim angle of the motor.
Verify that everyone in the boat is seated then push the throttle/shift lever forward to power up the motor.
Use the trim up button (also usually mounted on the throttle/shift lever) to slowly trim the motor up as the boat gains speed.
Adjust the trim slightly up or down once the boat is at cruising speed. If the trim is adjusted too far up, the boat will begin to "porpoise" as the bow starts to bounce up and down across the water. If the trim is adjusted too far down, the bow will start to plow into the waves, noticeably slowing the boat.
Continue adjusting if you speed up, slow down or encounter different currents or wave conditions.