The second 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 IV 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.