The jack plate allows operations in waters no deeper than your keel. Unlike power tilt or trim, which tilts your motor and drives your bow or stern downward into the water, the line along which the thrust is developed by the propeller when using the jack plate remains parallel to the optimum planing surface of the hull. The jack plate acts like an elevator for your outboard, raising and lowering the outboard motor, allowing you to go on- or off-plane more quickly, in shallower water, without driving the stern or bow of the vessel underwater.
Raise the jack plate (and the motor) to its uppermost position to travel through shallow water where your hull might pass, but your motor's propeller--below the keel of the boat--would otherwise prevent operations. This gives your vessel access to a wider range of operating areas without fear of a bent propeller or damaged lower unit.
Move your throttle to the "Wide Open Throttle" position while lowering the jack plate simultaneously. Your boat's transom (the back of the boat) will squat in the water slightly, and the prop will still be far enough out of the water to miss the bottom, yet deep enough to prevent propeller cavitation (the prop whipping air into the water, causing damaging air-implosions on its metal surface). The boat will begin to rise onto plane as you continue to lower the jack plate, until the propeller arrives at the proper level for remaining on plane, allowing high speed take-offs in hull-depth waters.
Raise the jack plate as you enter shallow waters, but continue at "Wide Open Throttle". Just before taking all way off of the boat (stopping it), use the tilt control to raise the engine's angle sharply. The stern (the back of the boat) will be at its lowest point coming off plane, but the engine will be in the "up" position and draft is minimized. This will raise the bow (the pointy end) and reduce the speed quickly. As soon as the bow comes up, move the throttle to the neutral position and simultaneously lower your engine angle with the tilt control. Speed will drop sharply and your motor will be in position at keel depth for shallow-water operation
Tips & Warnings
- Practice these maneuvers in open water before attempting them in shallow, constricted waters.
- Remember that even though you are temporarily bow-up when you stop, the bow of your boat will be sucked back down toward the bottom quickly when the boat stops. When performing a high-speed stop, all persons aboard should be seated or prepared for the sudden changes in the boat's motion.
- Photo Credit Jupiterimages/Photos.com/Getty Images
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