An unmanned sea vehicle is provided with a canister storing therein a net assembly in a deflated condition attached to the sea vehicle through the canister by a lanyard in a folded condition. The net assembly is connected to an inflation gas generator through which it is inflated to initiate retrieval of the unmanned sea vehicle. Inflation of the net assembly effects ejection thereof from the canister afloat onto a body of seawater, while connected to the canister on the sea vehicle by the unfolded lanyard. The floating net assembly is thereby positioned for engagement by a grappling hook lowered from a helicopter for example so as to lift it with the sea vehicle suspended therefrom by the lanyard from the sea water surface and transferred to the deck of a retrieval sea vessel.