What type of engine is mounted on the transom of a boat?

An outboard engine is specifically designed to be mounted on the transom, which is the vertical section at the back of a boat. This type of engine is often easily removable and typically includes the motor, propeller, and controls in one comprehensive unit. Outboard engines are popular for their versatility and ease of maintenance, as they can be tilted out of the water when not in use, protecting the propeller and lower unit.

In contrast, inboard engines are installed inside the hull of the boat, making them different from outboards in terms of installation and access. Auxiliary engines generally refer to additional power sources that can support or enhance a primary engine, while stern drives combine elements of both inboard and outboard systems but are mounted differently from traditional outboard engines. Each of these types has its own specific applications and advantages, but for direct transom mounting, the outboard engine is the correct answer.