Free Diving Between Scuba Dives Could Bend a Diver.

Dr. Robert Wong, an Australia Hyperbaric Physician, has reported how breath hold diving can cause decompression sickness, relying on an earlier Danish study by Dr. P. Paulev and work done by American Fred Bove, MD.

After spending eight minutes at 65 feet in a recompression chamber, Dr. Paulev performed about sixty breath hold dives in a submarine escape training tank to depths of 65 feet, with as much as a two minutes of bottom time and surface intervals of one to two minutes. He suffered from nausea, dizziness and belching. Later, he developed pain in his left hip, the right knee, the right arm was weak and … felt tired. There was also skin prickling and blurring of vision. He was recompressed and made a full recovery.

According to Bove, Paulev determined that ‘the short surface intervals did not allow tissue nitrogen to be eliminated and thus it was equivalent to that resulting from a continuous dive. … There are several stories of divers getting DCS from free diving after scuba diving. A surface interval spent free diving is not really a surface interval and the calculation of decompression will not be correct.

The best advice is to avoid free diving during surface intervals. If you want to snorkel, stay on the surface.

Abstracted from Dive New Zealand, June/July 2004
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