Mount Maunganui Underwater Club patron Russ Hawkins said the man was an experienced diver.
"He's very experienced. I would say he's been doing it for a long time, about 40-odd years I would say. It [the bends] doesn't happen very often ... [but] we're not sure this even is a 'bend'. It's hard to say," he said.
Mr Hawkins said the man had most probably been diving for crayfish at Okaparu Reef.
The TrustPower TECT rescue helicopter flew at least one or two divers suffering from the bends to the naval hospital every year, Mr Brettkelly said.
"It's the only place [to go for treatment] apparently."
Decompression sickness, or "the bends", occurs during a dive when nitrogen bubbles are absorbed into body tissue and the bloodstream. In extreme cases, divers can die if untreated.
BOP lb