Byford Dolphin diving accident in 1983 resulted in five deaths

On November 5, 1983, a rapid decompression event aboard the Byford Dolphin in the North Sea killed five men and left one survivor; investigators cited a premature unlatching of the diving bell and shortcomings in the rig's diving equipment.

On November 5, 1983, a rapid decompression incident occurred aboard the semi-submersible rig Byford Dolphin in the North Sea during a saturation diving operation. Six men were using compression chambers and a diving bell to move between their living quarters and the underwater work site at about 295 feet. Five of the six men died and one survived with serious injuries. Investigations afterwards pointed to a premature unlatching of the diving bell and to shortcomings in the rig's diving equipment. Key details: - Date and location: November 5, 1983, aboard the Byford Dolphin in the North Sea. - Casualties and injuries: five of six men died and one survived with major injuries. - Immediate cause reported: a premature opening/unlatching of the diving bell led to rapid decompression and related trauma. - Equipment concerns cited: the rig's diving system was described as outdated and lacked interlocking mechanisms, external pressure gauges, and other fail-safe features. Summary: Five of the six men aboard died and the sole survivor sustained major injuries; investigators reported a premature opening of the diving bell and outdated safety equipment as contributing factors. The Byford Dolphin was later decommissioned in 2019 and sold for demolition in the 2020s. Undetermined at this time.