By Lieutenant Commander Joel Hissink

THE scientific officer at the Submarine and Underwater Medicine Unit, John Pennefather, has completed 40 years of service to the Navy.

Commander Joint Health Rear Admiral Robyn Walker, a previous commander of the unit, attended a morning tea at HMAS Penguin on October 2 to present John with a long service award and a commemorative plaque.

Rear Admiral Walker said John was held in high regard among diving and submarine medical communities all over the world and continued to be asked for his opinion on a diverse range of underwater medicine topics. 

"John's 40 years of service and dedication to the continuing improvement of diving and submariner safety is unparalleled and is an admirable achievement," she said.

John said he was embarrassed by the award, but grateful that "people made a fuss".

"It was especially nice that Rear Admiral Walker was able to participate as I enjoyed working with her earlier in her career," he said.

He said one of the highlights of his career was helping to take the testing of the tower escape system in the Collins-class submarines to the stage where people conducted escapes.

John began working at the Submarine and Underwater Medicine Unit, then known as the School of Underwater Medicine, in 1972. As a young physiologist with an interest in animal climate physiology, and having studied the oxygen consumption of grazing sheep, he sent a letter addressed to the "The RAN, Canberra" outlining his design idea for a closed-circuit rebreather diving set. 

The letter reached the Submarine and Underwater Medicine Unit and John was invited to discuss his ideas. Soon after he was offered a job as the unit's scientific officer.

One of his first projects was working on a new oxygen diving set design in the mid-1970s. He also conducted research that found clearance diver trainees were burning more energy than they received, which led to increased food rations and more sleep while on course. 

He co-authored the highly regarded diving medicine textbook, Diving and Subaquatic Medicine, which is now in its fourth edition and regularly consulted by diving physicians across the globe. He has investigated hundreds of military and civilian diving accidents and has provided design advice on diving and hyperbaric-related equipment, ranging from portable two-man recompression chambers to methods to keep live fish fresh during transit.

He has taught divers about physiology and has educated medical officers and underwater medics in various aspects of underwater medicine.

John intends to retire next year but is eager to continue to provide expert advice to Navy in retirement.