Most Common Types of Boat Propulsion Systems and the Advantages of Each

If you're new to boating or deciding on what type of boat you want to get, you may feel overwhelmed with all of the options on the market. The three most common types of boat propulsion systems are sterndrive (inboard/outboard drive or I/O), inboard motors, and outboard motors. There are pros and cons to each, and we will briefly review them below.

Inboard Propulsion Systems

Boats with inboard propulsion systems have their engines mounted inside the hull of the boat, usually in the center. A driveshaft runs from the engine to the outside of the boat where it connects to a propeller. The way that power is created and delivered is very similar to how a car engine works. An inboard boat has a rudder mounted directly behind the propeller to enable steering. A disadvantage to this setup is that inboard boats cannot be effectively steered or maneuvered in reverse.

Unlike outboard and I/O boats, inboard boats can be left in the water year round. With inboard boats, the harmful components such as the prop are tucked safely away underneath the boat. Inboard boats usually also produce less wake and are a popular choice for those who like to participate in watersports such as skiing. If you're new to driving a boat, there is a considerably larger learning curve in maneuvering and trailering an inboard boat. In comparing inboards to the alternatives, inboard boats are easier and cheaper to maintain, have a lower center of gravity for better handling, and have a cleaner transom.

Outboard Propulsion Systems

Outboard propulsion systems have a unit mounted externally to the rear of the boat that contains the engine, gearbox, and propeller. These are the most common propulsion systems for boats. Not only does the unit provide propulsion, it also provides steering control all in one.

Outboard propulsion systems are generally more efficient and you can get more performance per horsepower compared to inboard and I/O boats. Outboard boat owners regularly praise how easy maintenance is due to the location of the motor. If you ever get into a bad situation in the water and don't want to do damage to the motor, you can simply trim it up and remove it completely out of the water. If you're not a DIY mechanic and regularly have your boat serviced when something needs repaired or maintained, regular auto mechanics are only going to know how to do so much. This isn't true with inboard or I/O boats as a regular car mechanic can service them.

Inboard/Outboard (I/O) or Sterndrive Propulsion Systems

Just as the name implies, an I/O boat has the drive unit, or outdrive, mounted to the rear of the boat with the engine sitting just forward of the transom, or rear of the boat. The outdrive delivers power from the engine to the propeller. The bottom half of an outdrive has a slight resemblance to an outboard motor.

Generally speaking, you can get more horsepower per dollar with I/O boats compared to inboard and outboard boats. A common complaint for I/O owners is that maintenance is difficult due to obstructed accessibility. I/O boats typically have more low end torque and a better hole shot than outboards. Maintenance costs are usually higher from year to year with an I/O boat compared to inboard and outboard boats.

Another consideration for I/O boats is the type of water that you will be operating the boat in. For various reasons, it's recommended to stay away from I/O boats if you're going to be using your boat in salt water.

No matter what type of boat you have or choose to purchase, Jet Dock's boat lifts are compatible.