A sea tractor is a motor vehicle designed to travel through shallow seawater, carrying passengers on a platform elevated above a submerged, tractor-like chassis. The sea tractor was most popular during the early 1930s, as a unique way to give scenic tours to patrons of waterfront hotels and resorts. In other applications, sea tractors were used merely as a ferry through shallow waters. Sea tractors are hardly used in present time – as boats, ferries, and other aquatic vessels often serve their function much more efficiently and comfortably.
The hotel at Burgh Island operates a sea tractor, to carry hotel guests and other visitors the 250 m (273 yd) to the island at high tide, when the causeway connecting the island to the mainland is submerged. The current tractor is the third one to be used at this location.
A sea tractor is also used at South Sands Beach near Salcombe, Devon. The beach has no jetty or pier and the South Sands Ferry therefore cannot reach dry land to pick up passengers. The sea tractor transports passengers to the ferry waiting a few metres out to sea.
The United States Army Corps of Engineers operates a three-wheeled sea tractor called the Coastal Research Amphibious Buggy (CRAB). This 8.2-tonne (18,000 lb) vehicle consists of a wheeled tripod supporting an operating platform 10.7 metres (35 ft) above ground level. It can move at 2 kilometres per hour (1.2 mph) on land and at a somewhat slower speed in water. It was built for scientific research on Beach nourishment.
The British and Irish maritime rescue organisation the Royal National Lifeboat Institution (RNLI) operates a number of different amphibious tractors for launching and recovering inshore lifeboats from beaches. These are wheeled or tracked vehicles capable of operating largely submerged, and some have cable winches. They include:
- Talus MB-H amphibious tractor, a tracked vehicle
- Talus MB-4H amphibious tractor, a wheeled vehicle
- Talus MB-764 amphibious tractor, a larger wheeled vehicle. One variant has a propeller for fully amphibious operation.
- RNLI New Holland TC45 launch tractor, a small agricultural tractor adapted for marine operation.
Ballybunion Sea and Cliff Rescue, based at Ballybunion in the west of Ireland, operates a specially constructed, tracked sea-tractor, used for launching and recovering the group's Atlantic 75-class lifeboat.
TV and movies
Sea tractors have been featured on the famous child's TV Show Teletubbies.
The Burgh Island sea tractor also appears as the method of transport between the mainland and the island in "Evil Under the Sun" (2001) episode of ITV's Agatha Christie's Poirot TV series. The second Burgh Island sea tractor features in the 1965 Dave Clark Five film Catch Us If You Can (1965). The Burgh Island sea tractor appears in the 1994 episode of the TV series Lovejoy "Somewhere: Over the Rainbow?" (episode 66 of 73).
- BARV, a tracked military vehicle designed to wade through seawater up to 3 metres (9 ft 10 in) deep.
- Brighton and Rottingdean Seashore Electric Railway, a late 19th-century railway that ran on submerged rails.