300 Whale Tail Hydrofoil Stabilizer – Fits Outboards & Stern Drives 40-350 HP
This universal whale tail hydrofoil stabilizer is designed to enhance your boat's performance, handling, and fuel efficiency. It mounts directly to the cavitation plate of most outboard motors and stern drives, offering a significant improvement in on-water stability and control for engines in the 40-350 HP range.
It serves as a direct replacement for models including the SE Sport 300, SeaSierra 300HS, PLSDDS 300, QuickMarine HS003, and NorthBoat FO2003.
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Installation Method: Mounts to the anti-ventilation (cavitation) plate. Drilling is required.
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Primary Material: Constructed from high-strength, UV-resistant Reinforced Nylon PA66 Plastic.
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Engine Compatibility: Fits most 2-stroke and 4-stroke outboard and stern drive engines from 40 to 350 HP.
Compatible Engine Models
Confirm your engine model/year in the table below. For Yamaha owners, here’s a guide to help you identify your engine’s serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson Serial Number Guide.
Confirm your engine model/year in the table below. For Suzuki owners, You can review exploded diagrams here to verify part numbers: Suzuki Parts Diagrams & Catalog.
| Brand |
Models |
Rated HP |
Stroke |
Years |
Notes |
| Yamaha |
Most Models |
40-350 HP |
2 & 4-Stroke |
All |
Except specific incompatibilities noted below |
| Mercury |
Most Models |
40-350 HP |
2 & 4-Stroke |
All |
Exception: Mercury 40 HP 4-Stroke incompatible |
| Johnson/Evinrude |
Most Models |
40-350 HP |
2 & 4-Stroke |
All |
- |
| Suzuki |
Most Models |
40-350 HP |
2 & 4-Stroke |
All |
- |
| Honda |
Most Models |
40-350 HP |
2 & 4-Stroke |
All |
- |
| Tohatsu |
Most Models |
40-350 HP |
2 & 4-Stroke |
All |
- |
| MerCruiser |
Most Sterndrives |
40-350 HP |
4-Stroke |
All |
- |
| Volvo Penta |
Most Sterndrives |
40-350 HP |
4-Stroke |
All |
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Technical Specifications
| Specification |
Value |
| Product Type |
Marine Hydrofoil Stabilizer |
| Installation |
Cavitation plate mount (anti-ventilation plate) |
| Material |
Marine Grade UV-Resistant Reinforced Nylon PA66 Plastic |
| Dimensions |
17.0-17.5" × 14.4-15.5" × 3.5" (432-445mm × 366-394mm × 89mm) |
| Weight |
1.38-1.79 kg (3.04-3.84 lbs) |
| Compatible Engine HP Range |
40-350 HP |
| Compatible Engine Types |
2-Stroke & 4-Stroke outboards, stern drives |
| Installation Hardware |
Included (screws, nuts, drill bit) |
Package Contents
- 1 x Hydrofoil Stabilizer
- 4 x Mounting Screws
- 4 x Mounting Nuts
- 1 x Drill Bit
- 1 x Installation Instructions
Installation Guide
This universal hydrofoil requires drilling for proper installation. Always follow the specific instructions included with your product. A general guide is as follows:
- Center the hydrofoil on the cavitation plate of your outboard or stern drive. Ensure it is positioned correctly according to the manual.
- With the hydrofoil held firmly in place, use a marker to mark the four drill hole locations on the cavitation plate.
- Remove the hydrofoil and carefully drill the four marked holes using the provided drill bit.
- Place the hydrofoil back onto the plate, aligning the holes.
- Insert the mounting screws from the top and secure them with the nuts from the bottom. Tighten securely.
- Check that the hardware is tight and does not interfere with the propeller's movement.
Troubleshooting & FAQ
How do I know if this hydrofoil fits my engine?
This hydrofoil is designed for universal fitment on most outboard and stern drive engines from 40 to 350 HP. Review the compatibility table and check the dimensions against your engine's cavitation plate. Note the specific exclusion for Mercury 40 HP 4-Stroke engines.
What are the main benefits of using this hydrofoil?
It improves performance by reducing bow rise, enabling faster planing at lower speeds, and enhancing overall stability and handling. This leads to a smoother ride, better fuel efficiency, and reduced porpoising or cavitation.
Do I have to drill holes in my engine to install this?
Yes, this hydrofoil requires drilling four holes into the cavitation (anti-ventilation) plate for secure mounting. All necessary hardware, including a drill bit, is included.
Will this work with a Mercury 40 HP 4-Stroke engine?
No, this hydrofoil is not compatible with Mercury 40 HP 4-Stroke models.
OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.