A small submarine that is able to reach the depths of the ocean or that is able to probe inside places that are too small for ordinary vessels.
small craft that operates underwater
A submersible is a small underwater vessel.
Research vessel designed to dive beneath the ocean surface. Deep-sea submersibles are designed to go to depths greater than ordinary submarines (depths greater than 2,000 meters).
a vessel capable of functioning under water.
A submarine vehicle used in oceanographic studies.
A submersible is a type of underwater vessel with limited mobility which is typically transported to its area of operation by a surface vessel or large submarine. Apart from size, the technical difference between a 'submersible' and a 'submarine' is that submersibles are not totally autonomous. They may rely on a support facility or vessel for charging of batteries, high pressure air, high pressure oxygen replenishment, or all of these.