US Navy tests saturation divers’ helium voice problem solution

U.S. Navy sailors from the Navy Experimental Diving Unit (NEDU) at Naval Support Activity Panama City (NSAPC) “re-surfaced” February 2 after completing an 11-day simulated dive in the Ocean Simulation Facility (OSF) by being compressed to the equivalent of a depth of 500 feet.

The NEDU sailors were decompressed and released from the OSF after 11 days of training and testing the HeliCom Matrix, a new communications system designed to compensate for helium-influenced speech during saturation dives.

While at depth inside the OSF, the sailors were breathing a pre-made mixture of 94 percent helium and 6 percent oxygen because at high pressures, normal air becomes toxic.

The HeliCom Matrix works by de-scrambling the diver’s voice, which sounds altered while breathing the helium in the mixed gasses used for saturation diving, said Chief Navy Diver Teague Mangiaracina.

The gas mixture was made in-house by NEDU personnel three weeks prior to the saturation dive, said Senior Chief Navy Diver Eric Wilson, master diver and team leader of the saturation dive. Pre-planning and pre-mixing allows for hominization and a mixing accuracy within .5 percent.

“We plan these dives a year in advance, possibly even more,” Mangiaracina said. “We knew we were installing this equipment and needed to plan the dive around the testing.”

“The importance of this dive was twofold,” said Cmdr. Jay Young, commanding officer of NEDU. “First was to test new equipment that we will use in future [saturation] dives and validate its operation, and second was to use this scenario as a training opportunity to maintain our proficiency for our watch teams and our divers to continue our saturation mission here at NEDU. This ensures we are prepared in the event we are called upon to support saturation diving operations in the fleet.”

NEDU is currently the only U.S. Navy command capable of conducting saturation diving. Its sailors use the OSF for testing and evaluation of equipment and procedures that are used in diving worldwide.