A diver in his thirties working for a subcontractor died during marine environment survey work off Yeosu. A colleague noticed something wrong and brought him up, but he could not be revived.

Authorities are examining the work plan, diving procedures and safety management as a whole, including the chain of contracts running from client to main contractor to subcontractor.

The hazards of commercial diving

Commercial diving is governed by rules on depth, bottom time and ascent rate. Departing from procedure can lead to decompression illness or oxygen-related incidents, which is why surface support personnel and communications systems are required.

In waters with a current, divers easily drift from their intended position, so scheduling work around slack water is treated as a basic principle.

A recurring structure

In offshore work accidents, the division of commissioning, contracting and actual labour across several tiers has repeatedly been criticised for dispersing responsibility for safety.

Legislation assigns safety management duties to the principal contractor, but how far these are observed on site often becomes clear only after an accident.

Labour authorities said they would take the necessary steps according to the findings. Procedures for supporting the bereaved family are also under way.