Network access is blocked in this session, so I could not live-check URLs. I’m citing only domains and documents I’m confident exist (manufacturer home pages, NASA Glenn, USCG NAVCEN, the Savitsky SNAME paper) and avoiding deep product-page links I can’t verify.
The best hydrofoil for most outboards from 40 to 150 hp is the SE Sport 300: it adds enough lift to cut bow rise and planing speed without the drag penalty of oversized wings, costs roughly $60 to $90, and mounts to the anti-ventilation plate with four bolts. If your motor is heavy (a modern four-stroke of 150 hp and up) or you refuse to drill, the SE Sport 400 no-drill clamp version is the pick. For 8 to 40 hp tillers and kickers, the SE Sport 200 or StingRay Junior. For a bolt-on that lasts the life of the boat, the aluminum Permatrim, model-matched to your gearcase. Below is the full ranking of 12, what each actually changes, and when a hydrofoil is the wrong fix.
What does a hydrofoil on an outboard actually do?
An outboard hydrofoil is a wing bolted to the anti-ventilation plate above the propeller. At speed it generates lift at the stern, which pushes the bow down, gets the hull onto plane at a lower speed, and reduces porpoising and bow rise during the hole shot. Lift scales with the square of speed, which is why a foil that feels inert at 8 mph is doing real work at 20 (see the NASA Glenn lift equation).
What it does not do is make your boat a hydrofoil craft. The hull still carries almost all the weight. The foil is a trim device, closer in function to a fixed trim tab than to the foiling boats in sailing coverage. Planing-hull behavior, including why stern-heavy boats porpoise, is laid out in Daniel Savitsky’s 1964 SNAME paper on planing hull design, still the reference naval architects use.
Will it save fuel or add top speed?
Usually neither, and the original claims of 20 to 30 percent fuel savings do not hold up. On a boat that already planes cleanly and trims well, a foil adds wetted area and drag, so expect a top-speed loss of 1 to 3 mph and no fuel gain at cruise. The fuel benefit is real only in one case: a boat that was running bow-high and plowing at 12 to 18 mph can now plane at that speed, and planing burns far less than plowing.
The honest list of benefits is: lower planing speed (typically 2 to 5 mph lower), faster hole shot with a load aft, less porpoising, better forward visibility while climbing onto plane, and less ventilation in tight turns. If none of those is your problem, skip the foil and spend the money on a prop.
Which problems are better fixed another way?
- Chronic bow rise on a heavy four-stroke: true trim tabs (Bennett, Lenco) fix this with independent side control and cost $400 to $1,200 installed. A foil is the $70 version.
- Slow hole shot but fine once planing: drop one inch of prop pitch or move to a four-blade before adding a foil.
- Porpoising at cruise: trim the motor down first. A foil masks a motor mounted too high or trimmed too far out.
- Motor ventilating in turns: check mounting height. A foil helps, but it should not be the only fix.
How do you choose the right size?
Match the foil to the horsepower band the maker specifies, then to your gearcase. Small-motor foils (8 to 40 hp) have short spans so they clear the hull and do not overpower a light transom. Large foils on a 25 hp tiller create steering torque and drag with no benefit. Standard-size foils for 40 hp and up are built around the common gearcase footprints from Mercury, Yamaha, Honda, Suzuki and Tohatsu. Compare your plate dimensions to the maker’s template before buying, especially on older OMC and Evinrude cases and on newer electric outboards, whose plates are often smaller or shaped differently.
Drill versus no drill is the second decision. Drilled mounts with through-bolts are more rigid and quieter. No-drill clamps avoid holes in an aluminum plate that corrodes around fasteners in salt water. Whichever you pick, use the stainless hardware supplied, isolate it from the aluminum with the nylon washers included, and inspect for crevice corrosion each season.
The 12 best outboard hydrofoils, ranked
| # | Model | Best for | HP range (maker) | Mount | Street price |
|---|---|---|---|---|---|
| 1 | SE Sport 300 | Overall, 40 to 150 hp | 40 to 300 hp | Drill | $60 to $90 |
| 2 | SE Sport 400 No-Drill | Heavy four-strokes, no holes | 40 hp and up | Clamp | $90 to $130 |
| 3 | Permatrim | Permanent, aluminum, model-fit | Model-specific, roughly 2 to 300 hp | Drill | $150 to $300 |
| 4 | StingRay XRIII | Turn stability, cupped tips | 40 hp and up | Drill | $80 to $120 |
| 5 | SE Sport 200 | Tillers and kickers | 8 to 40 hp | Drill | $40 to $60 |
| 6 | StingRay Junior | Small motors, alternate fit | 8 to 40 hp | Drill | $50 to $70 |
| 7 | Davis Doel-Fin | Budget, decades of use | Most outboards and sterndrives | Drill | $35 to $60 |
| 8 | StingRay Classic | Budget full-size | 40 hp and up | Drill | $60 to $90 |
| 9 | Davis Whale Tail XL | Large motors, stainless hardware | Larger outboards and I/Os | Drill | $70 to $110 |
| 10 | StingRay Starfire | Set-screw no-drill, small motors | Small to mid motors | Set screw | $50 to $80 |
| 11 | Lalizas / Nuova Rade hydrofoil | EU buyers, metric gearcases | 50 hp and up | Drill | €50 to €90 |
| 12 | Generic clones (Five Oceans, SeaSense, Shoreline) | Only if nothing else fits budget | Varies | Drill | $25 to $45 |
Prices are typical US street prices in late 2026 and move with retailer and season. Confirm current horsepower ranges and templates on the manufacturer sites: Sport Marine Technologies (SE Sport), Marine Dynamics (StingRay), Davis Instruments and Permatrim.
1. SE Sport 300
The narrow planform and cupped underside produce lift without the wide-span drag of older designs, which is why it loses the least top speed in our experience. Four-bolt drill mount, glass-filled nylon, black or white. The weak point is the same as every plastic foil: a hard grounding snaps a wing. Keep a spare if you run shallow.
2. SE Sport 400 No-Drill
Same wing family, larger, with a clamp system that grips the plate edges. The extra area suits 150 to 300 hp four-strokes hanging 450 to 600 lb off the transom. Re-torque the clamps after the first outing. Expect a slightly larger speed penalty than the 300 on boats that did not need the extra lift.
3. Permatrim
Powder-coated aluminum plate cut to a specific gearcase, so it fits flush with no overhang and no flex. It is the only foil here we have seen last ten seasons. It must be drilled, it costs two to four times the plastic options, and ordering the wrong model number is the usual failure mode. Shipping damage to the coating leads to corrosion if not touched up.
4. StingRay XRIII
Upturned tips reduce tip vortex and add grip in hard turns, which matters on bass boats and flats skiffs that run trimmed out. Slightly more drag than the SE Sport 300 in a straight line.
5. SE Sport 200 and 6. StingRay Junior
Both sized for 8 to 40 hp. Pick by plate fit. On a 20 hp tiller skiff the difference is a planing speed drop of 2 to 3 mph and a bow that stays down with two people aft. Neither helps a motor under about 8 hp, which rarely reaches speeds where the wing works.
7. Davis Doel-Fin and 9. Whale Tail XL
The Doel-Fin is the original mass-market foil, with a flat, wide planform. It works, it is cheap, and it creates more drag than the newer shapes. The Whale Tail XL scales it up for larger motors with stainless hardware. The older Davis mounting instructions assume a plate shape that some newer gearcases do not match, so check the template.
8. StingRay Classic and 10. Starfire
The Classic is the budget full-size StingRay with a simpler wing. The Starfire delta wing mounts with set screws, which avoids drilling but loosens over a season; use thread locker and check it monthly.
11. Lalizas / Nuova Rade
Lalizas, which owns Nuova Rade, sells a molded foil with stainless hardware that is easier to find than SE Sport or StingRay in Europe and the Mediterranean. Performance is in the Doel-Fin class.
12. Generic clones
Amazon-brand foils copy the Doel-Fin or StingRay shape in cheaper plastic. We have seen them crack at the bolt holes within a season. If budget rules, the Doel-Fin itself is only a few dollars more.
What has changed since the earlier lists?
Three things. First, the “Attwood hydrofoil” that appeared in older roundups is no longer a current Attwood catalog item; buy from the makers above instead. Second, average outboard weight keeps climbing as four-strokes replace two-strokes, so bow rise complaints and foil sales have grown rather than faded. Third, electric outboards from Torqeedo, ePropulsion and Mercury’s Avator line now show up on small boats, and their plate geometry often does not match any plastic foil template, so measure before ordering.
Does a hydrofoil void the outboard warranty?
Drilling the anti-ventilation plate does not, by itself, void a warranty under the major manufacturers’ terms, but damage a dealer traces to the foil (a cracked plate, a corroded bolt hole) will not be covered. If you are inside the warranty window on a new motor, the no-drill SE Sport 400 or the Starfire set-screw mount removes the argument.
Why bow rise is a safety problem, not just an annoyance
During the hole shot a bow-high boat blocks the operator’s view ahead for three to eight seconds. Navigation Rule 5 requires a proper lookout at all times (USCG NAVCEN, Navigation Rules), and the Coast Guard’s recreational boating statistics list operator inattention and improper lookout among the leading contributing factors in accidents (USCG Boating Safety Division). A foil that keeps the bow down through that window is cheap insurance on a crowded ramp.
What we learned shooting from camera boats
We run camera skiffs from 40 to 90 hp for on-water commercials, and the hydrofoil decision there is simple: the gimbal operator cannot work through porpoising. On a 17-foot center console with a 90 hp Yamaha four-stroke, an SE Sport 300 took our usable slow-plane speed from about 19 mph to 15, which is the speed a tracking shot of a wakeboarder or a sailboat actually needs. We lost 2 mph on top. For a chase boat that is a fair trade. For a client’s fishing boat built for the run to the grounds, we would not fit one.
Installation in 20 minutes
- Trailer the boat, tilt the motor, clean the plate.
- Center the foil on the plate with the leading edge even with or slightly behind the plate’s leading edge. Too far forward adds drag and spray.
- Mark, drill with a sharp bit sized to the kit, deburr, and seal holes with a marine sealant.
- Bolt with the supplied stainless hardware and nylon isolators. Torque evenly, then re-check after the first hour of running.
- Trim down for the hole shot, trim up at cruise, and expect to run one to two notches less trim than before.
Measure your anti-ventilation plate, note your horsepower and whether you will drill, then buy the SE Sport 300 for most motors over 40 hp, the SE Sport 400 if you will not drill or the motor is heavy, the SE Sport 200 or StingRay Junior under 40 hp, and the Permatrim if you want it to be the last one you buy. Fit it, run a known course at your old planing speed and at wide-open throttle, and keep it only if the planing-speed gain is worth the top-end loss on your boat.
