Last year I bought a 17' Lund fish/ski boat with a 115 E-Tec on it. One of my friends has an 18' boat with a 115 Mercury 4-stoke on it. He swears that the Sting Ray Hydrofoil he installed makes a world of difference and I should install one on my E-Tec. Would a hydrofoil make any difference on a 2-stroke like the E-Tec?
04-30-2012 05:56 - edited 04-30-2012 06:00
Although hydro-foils, such as the Sting Ray have advantages in SOME applications, the are in my opinion a "band-aid" for another problem. They also have a few "cons" along with the "pros" they offer in the cases where they help.
There are two common uses for one of these.
First is to correct porpoising, where the bow of the boat bounces up and down as the boat travels through the water. This symptom is USUALLY caused by the propeller loosing and regaining its grip with the water. A lower trim level normally correct the situation. If an aluminum or stainless 3-blade prop is in use, a 4-blade prop and/or an engine height adjustment usually fix the porpoising problem. An over-all gain in top speed can occur with the change to the engine set up, or switch of propeller style.
Second is to improve "hole shot" and get the boat on plane. Trouble getting a water skier up on the skis might be one example of a need to improve planing ability. A 3 or 4-blade stainless steel propeller usually does a better job in this situation too.
In either case, addition of a hydro foil can reduce top end speed, depending on how high the outboard is mounted on the transom, it can also induce some steering torque at certain engine trim settings, again this can depend on how high the outboard is mounted on the transom.
You didn't elaborate on whether or not you were experiencing a porpoising issue or just want to improve hole shot. Feel free to continue the discussion, but please provide us some info about your boat, the outboard set up, how you use it and what aspect of performance you want to attempt to improve.
Hope this helps,