Re: Which Hydrafoil Is Best
If hydrofoils were the answer to boat handling issues, the manufacturers of I/Os and Outboards would do the design work and make the cavitation plate bigger. The test that someone was refering to was done by Trailer Boats magazine about four years ago, and not much has changed today.<br />Small boats are no different than small airplanes. Small and large, slow and fast airplanes, have flaps, trim tabs, and rutters. What this does is adjust the airplanes' hull design to compensate for speed, load, wind currents, power (engine), etc. They don't use the engine to adjust attitude. Since air and water are both liquids, boat handling is not much different than an airplane. Since boats are designed with a rigid (non adjustable) hull, they all have one specific speed at which they perform their best. Anything either side of this will be a comprimise. Small boats usually plain easier than bigger boats simply because the power to weight ratio is better. So why don't manufacturers install trim tabs on small boats? Number one reason is expense! So on smaller boats, the manufacturers provide the motor trim which uses the prop to help lift the stern on take off! Why? Because it is safe! If helm controled trim tabs are used on small fast boats the inexperienced driver (or his 10 year old who is helping drive the boat) can mistakenly deploy one trim tabs and cause seriuos handling issues. So between cost and the possibility of missuse helm controlled trim tabs are seldom installed on boats under 22 ft. Hydrofoils are cheap, and they give lift, not much but some. Their effect at low speed is dependent upon the needs of the boat (balance). On Deep V boats lifting the boat from the center ( motor ) can create or exaggerate side to side instability, including pitching hard ( bow down) in turns and chine walk. Porpoising is usually reduced at higher speeds because of the extra lift on the stern, which causes extra bow pressure. This is usaully at the cost of top speed because the motor trim is fighting the stern lift. You never want to adjust boat attitude with the moror, it is simply not efficient. Everything is a comprimise, but boat handling is all about balance and the control of balance. Check out Smart Tabs by Nauticus (Nauticusinc.com)