Towed and Bottom-Crawling Vehicles. Towed vehicles are pulled through the water by a surface craft or winch. Some vehicles have limited propulsive power and are capable of limited maneuverability. Bottom-crawling vehicles use a wheel or track system to move across the seafloor, although some may be able to ‘swim’ limited distances. These vehicles are typically large and heavy, and are often designed for one specific task, such as cable burial.