Internal Drive Boats

A major progression in today’s boating industry is the use of Internal Drive systems, which is fast becoming the favorite choice of power delivery for recreational boaters. Internal drive refers to how the boat is actually being powered through the water.

Having an inboard/outboard drive, or stern drive, means the boat has an engine that is inside the boat (at the stern, or back of the boat) and a propeller that is outside the rear of the boat, which is submerged in the water while underway. A boat with internal drive also has an engine and a propeller, but both components are housed inside the boat. The internal propeller is in a tube that intakes water at boat speed, which is then accelerated through the drive unit and pushed out as a stream of water through a nozzle at the back of the boat at a high speed. As the water is expelled backwards, the boat moves forward. Internal drive works in relation to Newton’s Third Law of Motion – every action has an equal and opposite reaction.

Although internal drive boats have been around for years and manufacturers like Yamaha rank at the top of the marine industry for reliability and durability, today’s newest crop of internal drive systems are ultra-efficient and family-friendly and are now used in many of today’s best-selling recreational boats.

There are many benefits to using an internal drive system. Because internal drive systems use an internal propeller, water skiers, wakeboarders, swimmers, drivers, etc. are not exposed to external propellers. There is also less potential for damage to internal drive boats from floating debris, and there are no outside propellers to foul on stray ropes or fishing lines.

Internal drive boats also have expanded access to shallow waters. The potential for major drive damage from running aground, as with exposed propellers, is significantly minimized. Internal drive boats also have excellent maneuverability and acceleration compared to their stern-drive counterparts. Whatever the situation requires, the needed amount of thrust (the stream of water exiting the boat) can be directed forward or backward, left or right. This directed thrust results in very responsive steering and straight-line acceleration.

There are also comfort benefits to internal drive systems. Compared to stern drive systems with an exposed propeller, internal drives greatly reduce onboard noise and vibration levels. This is because internal drives rotate at higher speeds and the propellers are encased.

Remember, all boats use propellers. The difference is that an internal drive has no exposed propeller and a stern-drive does. It’s that simple.