Many ships had lead plates laid on their underwater surface.

The underwater surface has many of the same features as the above sea with volcanos, mountains and trenches or canyons.

The proliferation of high-speed threats be they underwater, surface or aerial threats required the development of effective defences.

A tube worm is a worm-like sessile invertebrate which anchors its tail to an underwater surface.

An innovative plastic film was applied to the underwater surface of the hull to reduce drag.

While most such underwater sedimentary surfaces are generally smooth, some are rough in texture.

They and their larvae spread rapidly by hitchhiking in bilge water and on the underwater surfaces of boats.

A spawning bed is an underwater solid surface on which fish spawn to reproduce themselves.

The mission involved considerable diving and the inspection of the underwater surfaces of many grounded vessels.

Kill or repel organisms that attach to underwater surfaces, such as boat bottoms.