Jack Plates

What Is a Marine Jack Plate?

A jack plate is a mounting system installed between a boat's transom and its outboard motor. Jack plates allow the engine to be raised or lowered vertically, changing how the propeller sits in the water — and that seemingly simple adjustment unlocks a surprising range of performance and safety benefits. Whether you fish shallow flats, run open bays, or push your hull for maximum speed, a jack plate gives you the control to optimize your outboard for every condition.

Why Jack Plates Matter for Outboard Performance

At the heart of the jack plate's value is the relationship between engine height, drag, and efficiency. Lifting the engine higher in the water reduces drag, resulting in increased speed at the same RPM and better fuel economy. Beyond straight-line speed, jack plates also provide critical setback — moving the engine further behind the transom so the propeller accesses cleaner, undisturbed water away from the turbulence generated by the hull. This setback adds leverage that helps raise the bow and improves overall planing behavior.

For anglers and boaters who navigate shallow or variable-depth water, hydraulic jack plates are especially valuable. With the touch of a button, you can raise the engine so the boat accesses shallower water, reducing the risk of prop strikes and allowing you to explore tight creeks, flats, and inshore backwaters that would otherwise be off-limits. When conditions get rough, lowering the engine deeper helps the vessel stay on plane and maintain stability. For boats stored in the water, lifting the motor completely clear of the waterline also helps minimize galvanic corrosion on the lower unit.

Manual vs. Hydraulic Jack Plates

• Manual Jack Plates: Adjusted by hand using bolts or a threaded mechanism. Simple, durable, and cost-effective — ideal for boaters who want to set engine height once and leave it. Best suited for consistent water conditions.
• Hydraulic Jack Plates: Allow on-the-fly engine height adjustments at the push of a button while underway. Ideal for boaters who regularly move between shallow and open water, or who want real-time performance tuning for changing loads and conditions.

Key Considerations When Shopping Jack Plates

When selecting a jack plate, the most important factors are your outboard's horsepower and weight, your typical water depth, how frequently you plan to adjust engine height, and the amount of setback your hull benefits from. Setback is commonly available from 4 inches up to 14 inches, and choosing the right dimension depends on your boat's hull design and engine size. Always verify the plate's rated horsepower and maximum engine weight before purchasing.

Top Jack Plate Brands

Bob's Machine is widely regarded as the pioneer of the hydraulic jack plate, having introduced their first model in 1978. Their Standard Series and Action Series hydraulic jack plates come with a lifetime structural warranty and are manufactured in the USA, covering engines from 35 to 300 HP across setbacks ranging from 4 to 14 inches — all in a one-piece design that eliminates the need for setback spacers.

SeaStar Solutions brings decades of marine engineering expertise to the jack plate market. Their Gen II Standard and Xtreme hydraulic jack plate lines feature rapid hydraulic response, a high-output integrated actuator, and sleek styling designed to complement SeaStar's own steering cylinders — making them a natural fit for boaters building a fully integrated helm and transom system.

CMC has built a loyal following with their Power-Lift jack plate line, a classic roller-style design known for its versatility and reliability. Available in multiple setback configurations, CMC plates are a dependable choice for boaters seeking proven hydraulic performance with broad outboard compatibility.