This Week in History - 12 June

In 1811 an Ensign in Her Majesty's Royal Navy, Mr. Cedric Mortenay, approached the Admiralty with an ingenious plan. He proposed to build a ship that could hide from an enemy by submerging beneath the sea for short periods of time. The vessel would be built from oak like most of the existing British vessels. However there would be a few major differences. The hatches would all seal water tight. A large area of the hold would be taken over with a series of holding tanks into which water could be pumped to allow the ship to submerge. When the vessel wanted to resurface the water would be pumped out of the holding tanks which would increase the buoyancy of the vessel allowing it to rise. The pumps would be hand operated by the crew. The submerged time would be limited to one hour, the estimated amount of time that the air on board would support the crew.

The Admiralty was very impressed with the idea and authorized young Mortenay to immediately begin working on his vessel. The work authorization carried with it a promotion to lieutenant.

One year to the day that construction had begun the H.M.S. Poseidon slipped free from it's moorings and drifted into the center of London Harbor. With most of the British Admiralty in attendance as well as members of the royal family, the men of the H.M.S. Poseidon received the order to submerge.

The plans called for the ship to simply submerge from sight, wait one hour and resurface. Maneuvering under the water was not expected nor planned for.

As the hull slipped beneath the surface the viewing audience was breathless with anticipation. But the excitement was soon replaced with shouts of anger and outrage. The vessel had worked perfectly, the hull had slipped quietly beneath the surface and disappeared from sight. However the masts with all sails rigged and flags flying was still completely visible to all except the blind.

As the vessel resurfaced an hour later the a red-faced admiral was waiting on the deck when the hatches open and the young lieutenant emerged. Ripping the officers epaulets from the young mans shoulders the admiral began a long tirade about the waste of time manpower and funds. Lt. Mortenay managed to calm the admiral and convinced him that this was a minor setback. They could increase the size of the holding tanks and therefore take on more water and allow the entire vessel, masts and all to submerge.

After much debate they decided that it would be a shame to waste the funds already expended and authorized the Lieutenant a six month extension to refit the vessel with larger tanks.

Five months later the H.M.S. Poseidon once again sailed into the center of London Harbor. Received the order to submerge. And promptly disappeared from sight, hull, masts, sails, and flags.

Unfortunately the increased depth to which the hull was subjected, created too much pressure around the cannon ports and the integrity of the hull was violated and she began to take on water. As Lt. Mortenay ordered all hands to the pumps the outgoing currents of the harbor caught the sails and the began moving the vessel into the open waters of the English Channel.

The H.M.S. Poseidon, Lt. Mortenay and his crew of 40 sailors were never recovered. However his family received a posthumous award of Her Majesties Award of Honor because their son had indeed designed, built, and sailed the sneakiest ship in the fleet.