These are the reports.
I. INCIDENT BRIEF
17 Nov 2002: Duty IO received call from duty watchstander reporting death of diver on board NEKTON RORQUAL. NEKTON RORQUAL was conducting a 6- day dive cruise when one diver was spotted unconscious in 60 feet of water. Diver's buddy replaced respirator, which had been removed due to convulsions, and began surfacing. Diver surfaced with no vitals. Diver received CPR for 90 minutes by fellow diver. Diver did not respond, and pronounced deceased. Cause of death unknown.
I. INCIDENT BRIEF
On or about 1630 on January 6, 2002, while on a dive excursion aboard the SPV NEKTON RORQUAL in the vicinity of the Exuma Cays, Bahamas, Mr. Ronald Dean Grounds experienced a cardiac episode, from which he did not recover. Mr. Grounds subsequently expired 25 minutes after all attempts to revive him were effected. There is no evidence of misconduct or negligence on the part of the operator of the vessel or its crew. See Findings of Fact for details.
On 6/20/2005
MISLE Activity Number: 2398048
Originating Unit: Sector Miami
MISLE Activity Owner: Commandant (CG-385)
MISLE Activity Controller: Commandant (CG-385)
MISLE Case Number: 237682
I. INCIDENT BRIEF
A divemaster, functioning on the vessel as an engineer, drowned while free diving alone. The Coast Guard flight surgeon pronounced death.
I don't know if this is only in US waters
Here is the source:
USCG Incident Investigation Reports (Online)