A system is disclosed for pre-positioning a canister assembly at an undersea location. A transporter deploys to and releases the assembly proximate to the desired location. Once the assembly has fallen a safe distance after release, spring bands of the assembly are released by the action of lanyards of the transporter. The release allows anchor plates on each end of the assembly to separate from the assembly thereby dragging the assembly to a seafloor with the assembly buoyant at the undersea location. A vehicle deployment from the assembly is actuated by an acoustic receiver that causes a release device to release a normally compressed spring thereby allowing the spring to expand. During expansion, water is drawn into the assembly through flow ports to force a plunger plate with the water to act on a vehicle to deploy the vehicle out of a deployment tube of the assembly.