The first in a series of limited production collectible “Helmets in History” challenge coins produced for and sold by the Historical Diving Society USA. Each coin in the series will highlight a diving helmet with a positive impact on deep sea diving.
Every coin produced has the original HDS logo of an Augustus Siebe helmet on one side and the featured “Helmets in History” helmet on the reverse. This coin features the U.S. Navy Mark XII helmet.
These collectible coins are 1.75″ in diameter, are highly detailed, and will be a prized possession for years to come. Each comes in a soft PVC envelope.The USN Mark XII helmet was introduced into the navy in the early 1980’s as the replacement for the USN Mark V helmet. The shell is made from fiberglass and it is a free-flow system helmet. It was manufactured solely by the Morse Diving Equipment Company of Boston, Mass.