Grady-White Boats Marlin 300, Owner'S Manual

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A R L I N
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Trim Tabs
Trim tabs are electrically and hydraulically operated. The trim tab system includes a hydraulic
pump, a switch with an integrated indicator, and an auto-retract feature. The switch controls
the pump which lowers and raises the trim tabs. The indicator keeps you constantly aware of
the trim tab’s position. The auto-retract feature automatically raises the tabs every time the
ignition switch is turned off.
Trim tabs are used to regulate the attitude of the boat while moving and will aid in trimming
the boat fore and aft for a smoother ride. Trim tabs can improve the ride of your boat by
adjusting where the water is hitting the keel line. In a slight chop, the waves may be hitting the
keel of your boat around the helm area causing an uncomfortable ride. By adjusting the trim
tabs and lowering the bow, the waves will hit the keel at a more forward point and soften the
ride. Experimenting with trim tabs in various sea conditions will help you determine the best
positions for your boat under different load conditions
Trim tabs are also useful in correcting a port or starboard running list. If the boat is listing to
the port side, press the starboard trim tab switch toward “bow down”. Press the port trim tab
switch toward “bow down” to correct a starboard list. This will tend to lower the bow by
pulling the higher side to a level position. If your bow is already in a low position and your
tabs are down, you may correct a listing condition by pressing the trim tab switch toward
“bow up”. This will cause the low side to rise and level the boat. The running angle will also
gradually improve.
Trim tabs in the extreme “bow up” positions will have no effect on the boat's ride. Trim tabs in
the extreme “bow down” position will cause the boat to come on plane with minimum bow
rise. Unless you are operating at low speeds or with considerable cockpit weight you will
likely want to raise the tabs slightly when underway to avoid “plowing” water. With the tabs
in the “bow down” position, you will be able to maintain a plane at the least possible RPMs.
Trim Tab Pump Location
The trim tab pump is located in the rigging area behind the port wall of the aft berth. To access
the pump remove the wall. The hydraulic fluid should be checked on a seasonal basis.
N O T I C E
Most drive units are equipped with an adjustable rudder trim tab. This trim tab should be
adjusted to balance the steering at the speed which you travel most frequently. Variations in
speed, boat load, or changes in the drive unit trim will cause the steering to pull in one direction. If
the boat pulls to the left, adjust the trim tab to the left and vice versa.