Abstract: An amphibious all-terrain tracklaying vehicle has a pontoon hull (2) with propulsion track (1) juxtaposed from outside edges to central portions of the pontoon hull (2). A prime mover (11) and control center (22) are positioned on a deck framework (19) above the pontoon hull (2). Attachable optionally to the pontoon hull (2) are earth-moving, wetland-clearing, wetland-farming, snow-moving, rescuing, fire-fighting, spraying, cargo-transporting, personnel-transporting and other items (23). Track-cleaning and track-support elements which enable full-width juxtaposed track on a pontoon hull are provided.

Abstract: An air-boat (2) is provided with a hollow suspension member (4) through which a plow attachment member (3) is insertable to contain plowshare members (10 and 17) at a front section of the air-boat (2). There can be a plurality of hollow suspension members (4) and a hoist (6-9) with mechanical or motorized operation to adjust height and width positioning of the plowshare members (10 and 17). The plowshare members (10) can be V-shaped moldboard surfaces for forming ditches in mud, slime or marsh-bottom deposits. Optionally, the plowshare members can be blades (17) with either sharp, flat or rounded surfaces for parting water plants to form waterways in bodies of water. Methods are provided for forming drain ditches in slime beds and waterways in lakes with thick water-plant growth.