The amphibious supporting and propelling apparatus is intended for use in amphibious transport, in particular in seagoing all-terrain vehicles on air-supported caterpillar tracks. The apparatus comprises a caterpillar chain (1) constructed over the entire width of the distance between lateral enclosures of a body which is formed by said enclosures and by a three-dimensional dividing platform (8). A rational mutual positioning of the lower surface (15) of the above-mentioned platform (8), of upper and lower bending-round shapes of the chain (1) and of skids (4) is specified. The dimensions of pneumatic floats (2), which are in the form of cylinders of large diameter together with elements of transverse rigidity, are defined from the condition of ensuring the necessary clearance of the skids (4), traction on a slope, retaining the chain (1) on a lateral slope and gentle action on tundra soil under a large load capacity. The vehicle may have a number of caterpillar tracks. During operation, a high degree of buoyancy of the pneumatic floats (2) ensures reliable exit from water onto ice; and the clearance of the skids (4) ensures safe operation in a surf strip and high speed over unevenesses of soil and ice. The invention makes it possible to increase the reliability and efficiency of operation in coast and shelf conditions of freezing seas.