Mark V

An icon of deep sea diving, the Mark V Dress represents the early 20th century innovation in marine technology that enabled divers to work at significant depths for the first time. It was used by the U.S. Navy from 1916-1984, and is still used in the commercial industry in environments with especially strong currents.

Mark V Helmet and Breastplate

Weighing a little over 55lbs, the Mark V helmet and breastplate are made of spun copper and tobin bronze. The helmet is screwed down a quarter turn onto the breastplate, which is attached to the canvas dress with four brails. The hat has four glass ports, including the front faceplate, which opens outward.

Weight Belt

Used for buoyancy control, the leather weight belt keeps the diver submerged when his lungs expand during natural intake of breath, and as the dress inflates. The belt is attached with adjustable harnesses and a crotch strap, and its lead blocks weigh a total of 84lbs.


A flashlight is taped to the handle of the helmet to provide the diver with additional light for night dives, murky waters or other low-visibility conditions.


These lead-soled canvas boots with brass toe caps are attached with line and a leather strap. Each boot weighs 17.5lbs.

Mark V Helmet

The hat has four glass ports, including the front faceplate, which opens outward. Between the faceplate and side port, the spit cock allows the diver to suck water into his mouth and spit it at the faceplate to defog. Shown in detail: communication port (left) and air port (right).

Mark V Dress

Made of canvas and rubber, the Mark V dress with all its accessories weigh about 30lbs. The diver’s umbilical, including air hoses, lifeline and communication line, is not shown.