Even thou we sell mainly boat propellers, we are avid boaters as well and here is some advice we picked up: If you want your boat to get up and plane off quicker because it is too slow to do that or you want quicker starts to pull water skiers and or tubes & towables, you can do three things to accomplish that without having to re-power your boat or buy another boat with more power.
The first thing you can do is check out your propeller to make sure it is not damaged. A damaged boat prop can rob you of a lot of performance depending on how bad it is. You should find out what diameter and pitch your prop is and if it gets you in your recommended wide open throttle RPM (revolutions per minute) range for your engine. This RPM range is important because the most horse power for your engine creates is at a certain RPM and the range gives the boater a general area of RPM’s he can operate his boat at full speed without causing damage to his engine and to give him the most power and best performance his engine is going to make. Boat propellers can be thought of as gears. Different pitch sizes create different RPM’s all through the operating range. If you have too low of a pitch size prop you will over rev your engine at full speed causing possible damage to the engine. Too high of a pitch prop will cause the boat to take off slowly when you go full throttle from a standing start. You can use a lower pitch propeller for better take off, just do not go over your recommended wide open throttle RPM range at full speed. If you have a three blade propeller on your boat you can go to a four or even a five blade propeller to improve on the time the boat takes to get up on plane. For more information on boat props and how to prop your boat and also what kind of propeller you can use for quicker take offs, please read our articles “Boat Propeller Selection” and “Three, Four and Five Blade Propellers” found on our blog here.
The second thing you can do is put on some kind of hydrofoil to your cavition plate on your drive systems lower unit. These hydrofoils look like wings and are designed to help lift the stern of the boat at initial take off which makes the boat get up on plane quicker. They are made of either aluminum or some kind of composit plastic material. They come either as two separate wings you mount on the sides of the cavitation plate or as a one piece wing that goes all across the plate. We cannot really recommend the two piece hydrofoils because in quick hard turns they are known to snap part of the cavitation plate off, because of too much stress on the two seperate sides. The one piece hydrofoils tend to spread the stress all across both sides and damage from turning is greatly reduced. You mount them directly on to your cavition plate which is the flat plate above your boat propeller, usually by drilling 4 holes 1/4″ in diameter in the plate and then securing the hydrofoil with 1/4″ bolts and nuts. These hydrofoils generally word pretty well and get you boat planed off a little faster and they cost from under a hundred dollars to a maybe a few hundred dollars.
The third thing you can do is add trim tabs to your boat. These tabs are flat thin plates made out of aluminum and are usually 12 to 24 inches long and 6 to 12 wide, they do come in other sizes too depending on how big a boat you have and size you need to have them work right. They mount to the stern of the boat all the way down on the bottom on either side of the drive unit all the way out to the side of the boat. You drill holes through the stern and secure them with screws and silicone. At initial take off you have them angled down below the bottom of the boat so once you start going the water flows under the boat hull to the tabs which forces the water down at that point and thus raises the stern a little so you plane off faster. Once you are getting on to plane you adjust them up so they do not create a drag once you are going faster. You can also ajust the side level of the boat, once under way by adjusting the seperate sides. You can get trim tabs that adjust themselves using water pressure only and they work pretty well but there is not much boat side adjustment to them. The best ones are the hydraulic/electric tabs that you control right at the helm. They are more expensive and you have to install wiring and drill holes inside the boat and this is not really something most boat owners want to tackle so you need to also pay someone that knows what they are doing to do this for you.
You can use one, two or all three of these things on your boat. Start with the propeller first then maybe a hydroil and if it still is slow to plane, trim tabs. If your boat is 23 feet or longer you should have trim tabs on it any way no matter what so you have better control on how it rides on the water.