Inboards are found mostly on larger rigid inflatables. They are heavier and bulkier but more powerful, and, since diesel versions exist, they are common on equipped tenders.
Since low-horsepower inboard motors are rarely available, they are usually found on larger craft.
A rigid inflatable has its inboard motor aft or amidships, its position being critical for proper stability under way. Most are diesel, but gasoline versions exist.
Power is transmitted via a drive shaft connected to the propeller, which is fixed. A rudder and adjustable trim tabs to control trim are necessary. Pod drives and similar arrangements allow directing the thrust, as with an outboard. The engine compartment must be ventilated and often serves as an aft sundeck.
The inboard version of the rigid inflatable offers the seaworthiness of this type of craft, while providing motor options with more power and lower fuel consumption. It should be kept in mind, however, that trailering can be more difficult than with an outboard because of the shaft and propeller.