Self-propelled boat movers are not strictly trailers, but hydraulically operated boat movers, with their own tractor unit. They share all of the features of hydraulic boat trailers.
Non-commercial boat trailers
This type of trailer is usually used by the boat owner/operator. The trailer is also used for storage.
Roll-on, also known as a "Roller style trailer", uses rubber and/or polyurethane rollers for ease of launching and loading a boat.
Glide-path, also known as a "Float-on style trailer", allows the boat to float onto the trailer; after the trailer has been partially submerged (usually 3⁄4 of the trailer). Since its inception, it has become quite popular compared to the "Roller style trailer".
See also
Boat dolly, a device for launching small boats not suitable for towing.