Are you having trouble now? Doel fins, stingrays, whaletales, etc. do work. Sometimes they will take a little off your top speed...sometimes they will add to it. (The height of the device should be in line with the bottom of the boat and you can experiment a little if you have an outboard.)<br /><br />Smart tabs are suppoed to be even better, but cost more. If you do a search on any of the above key words, there will be tons of testimonials, opinions, and explanations on this subject.
Hydrofoils such as Dol-fin, SE Sport ect. seem to most effective on boats up to around 16-18 foot.<br /><br />How well they work really depends on your set up. Boat (size and type) and engine size factor in promprominently.<br /><br />If you will give some information I think you'll get responses that are more likely to be of help you.
Those fin things are hydrofoils meant to give lift like an airplane wing, and they do work, BUT their size limits how much lift they can provide, so a small or light boat will see more effect than a larger heavier boat.
