Bahamas Maritime Authority issued a Safety Alert raise awareness of the serious hazards associated with Hydrogen Sulphide (H₂S). It also highlights the requirement for risk assessment and precautions to be in place prior to opening any enclosed space that may contain this, or any other, toxic gas. It is based on the preliminary findings of a marine safety investigation, the second very serious marine casualty involving hydrogen sulphide that The Bahamas fleet suffered in 2025.
On 23 December 2025, a Bahamas flagged passenger vessel experienced a toxic gas release when three crew members unsealed a manhole cover for a ballast water tank being used to store grey water. A fourth crew member supervising the job was standing a few meters away. Their task was to open the tank for stripping with an external pump, which did not involve tank entry. An enclosed space entry permit was not issued.
When the manhole cover for the tank was unsealed, the crew heard a sound indicating a release of gas. The three crew in the immediate area of the manhole lost consciousness within a few seconds. The fourth crew member left the compartment after opening the nearest watertight door and radioed for help, initiating a Code Alpha medical emergency response.
The opening of the watertight door allowed an ingress of air to the compartment, providing temporary relief to the incapacitated crew, and they evacuated after regaining consciousness. During the emergency response, three additional crew members lost consciousness near the unsealed tank, later being removed from the space by crew.
Two crew members died, and five were hospitalised ashore and subsequently discharged. Their symptoms, along with testimony from crew are consistent with exposure to H₂S gas.
This is an ongoing investigation, and a marine safety investigation report will be published in due course.