SeaSierra Boat Hydrofoil Stabilizer for 40–300 HP Outboards and Sterndrives, Silver, 17"×14.4" Durable Trim Tab

The SeaSierra Boat Hydrofoil Stabilizer is a bolt-on trim tab that reduces bow rise, shortens planing time, and improves handling for 40–300 HP outboard motors and many sterndrives.

Designed for anglers, family boats, and performance small craft, this hydrofoil helps your boat get on plane faster, hold a flatter trim at lower speeds, and respond more predictably in rough water. Built of durable materials and supplied with mounting hardware and a pilot drill bit, it fits most popular outboard brands and many sterndrive models with horsepower from 40 to 300.

How does the SeaSierra hydrofoil change planing and fuel efficiency?

By creating downward lift aft of the propeller, the hydrofoil reduces bow rise and helps the hull plane sooner. That means less throttle is needed to reach hull speed, which can lower fuel use during acceleration and steady cruising. Effects vary with hull design and load.

• Shortens planing time for quicker acceleration
• Maintains plane at lower speeds for gentler throttle control
• Improves thrust direction and reduces bow climb under power

Which engines and sterndrives are compatible with this stabilizer?

The SeaSierra unit fits a wide range of outboard motors from leading manufacturers and common Mercruiser/OMC sterndrives. It covers Yamaha, Mercury, Johnson, Evinrude, Honda, Suzuki, and Tohatsu outboards rated 40–300 HP, plus many Mercruiser/OMC stern drives. Note: some Volvo sterndrive models require extra hardware and the Ocean Series XDP is not compatible.

• Works with 40–300 HP outboards from major brands
• Compatible with Mercruiser/OMC sterndrives
• Volvo SX-A, DPS, DPR, DPH, 280, 290 need longer bolts and 1" fender washers
• Not compatible with Volvo Ocean Series XDP

What comes in the box and what are the dimensions?

The package contains everything required to mount the hydrofoil: the stabilizer plate, four sets of stainless steel screws and nuts, and a 6.5 mm drill bit to pilot the mounting holes. The foil measures approximately 17 inches tall by 14.4 inches wide, sized to provide useful lift behind mid- and large-sized outboards and sterndrives.

• Dimensions: Height 17" × Width 14.4"
• Includes 1 stabilizer, 4 sets stainless screws and nuts, 6.5 mm drill bit
• Hardware accommodates most transom and lower-unit mounting locations

How difficult is installation and what tools are needed?

Installation is straightforward for anyone comfortable drilling and bolting to a lower unit or transom bracket. Use the included 6.5 mm drill bit to pilot holes, then fasten with the supplied stainless hardware. For Volvo SX-A, DPS, DPR, DPH, 280, and 290 sterndrive models, you will also need longer bolts and 1" fender washers (not included).

• Requires drilling pilot holes using included drill bit
• Fasten with supplied stainless screws and nuts
• Additional longer bolts and 1" fender washers needed for specified Volvo models

Who is this for: The SeaSierra hydrofoil stabilizer is aimed at boat owners who want easier, more controlled acceleration, better low-speed plane holding, and improved handling without complex trim systems. It's a practical upgrade for fishermen, recreational boaters, and anyone with a 40–300 HP outboard or supported sterndrive seeking a bolt-on performance and handling improvement.