A marine pressure minesweeping and ship signature simulating vehicle havingn inflated substantially doughnut shaped tubular float surrounding a pressurized air-filled cavity. The lower part of said float rides on the surface of the water and the upper part thereof is closed with a resilient membrane, upon the upper side of which is mounted water ballast container means, which is sufficiently open at the top to allow the water ballast to be ejected therefrom, as a result of a considerable increase in air pressure occurring in the aforesaid air filled cavity, due to a mine explosion. A motor driven fan maintains a suitable air pressure in said air-filled cavity at substantially all times, and drive and steering means are mounted on the vehicle in such manner as to enable it to be navigated along a desired course. The length of ship simulation pressure signatures may be varied by varying the number of vehicles connected in tandem, and the amount of water ballast employed may be varied according to the tonage of the ship being simulated at any given time.