Innie or Outie? Inboard and Outboard Motors for Boats

Inboard motors are high-performance engines repurposed for marine use from their typical automotive application. They are mounted in the center of the boat as a direct-drive system, or stowed inside the transom as a V-drive system. In both cases, the drive train and prop are built directly into the hull. The advantages of inboard engines is that they have excellent fuel efficiency, are relatively quiet, last longer compared to outboard motors, and have superior torque and power. They are commonly used in water sports like wakeboarding and waterskiing, as they have better wake control, towing power, and a clear transom for tow ropes. They also have a lower center of gravity, which helps cutting through heavy ocean waves. However, mounting the engine inside the hull reduces interior space for storage, they cost more upfront, are more labor-intensive in terms of maintenance, and require the boat to be fully winterized. 

Outboard motors are independent engines that are mounted onto the exterior of the transom. Outboard motors can be operated via a dashboard console or via a handle connected directly to the motor. Outboards have the advantages of being fully portable, much easier to maintain and winterize, save space on the boat for storage, are cheaper, and have a higher potential top speed. They can also be tilted up and out of the water, making it safer to use in shallow waters. They are often used for fishing, speedboats, and party boats. However, outboard engines lack the total torque to drive heavier boats. This issue is typically overcome by adding a second engine mounted to the boat, but this can negate the advantage of being less expensive compared to inboard engines.