A hydrofoil can improve the performance of a boat in numerous situations. But many people shy away from trying them, particularly because most require drilling holes in the lower unit’s anti-ventilation plate during installation. There are exceptions, but experience has proven that the clamp-on versions often come loose after a few seasons. So, how do you know if a hydrofoil is right for your boat?
First, ask yourself if your boat really needs it. The major benefits usually include:
- An improvement in running attitude for boats that tend to run with the bow too high.
- A slight improvement in cruising speeds (usually two or three MPH, though in extreme cases it can be higher).
- An improved hole-shot.
- A reduction in side-to-side rocking and rolling on powercats.
First let’s address powercats, because it’s a simpler issue with this type of boat. You shouldn’t expect much of a change in performance, but installing hydrofoils can reduce the “snap roll” some cats experience. On my boat, I think they offer about a 15 to 20 percent reduction in side-to-side motion.
In the case of most other boats, the simplest way to figure out if a hydrofoil will be beneficial is to judge by the boat’s running attitude. Boats that perpetually run bow-high are the most likely to see a benefit. This can be due to an under-power situation, weight distribution issues, or hull designs that don’t respond well to trim. And in all of these cases, a hydrofoil is quite likely to improve your boat’s performance. If, on the other hand, your boat responds well to trim, runs in a level attitude, and hops up on plane quickly and easily, you’re not likely to see much of a benefit from installing a hydrofoil.
All of that said, you’re still faced with the issue of drilling holes, with no assurances. The best solution? Start off with a clamp-on hydrofoil. If you see the benefits you were hoping for, then get the real deal and start drilling. And if you don’t, well, you’ll be out a few bucks but at least you won’t have those holes in your anti-ventilation plate.