Vessels responding to situations like that of Deepwater Horizon may encounter unexpected hazards with which they are unfamiliar and which are not immediately apparent.
A respondent on the gCaptain forum, Nomad, warns: “For any mariners responding to distress calls in circumstances such as this, it’s a good idea to stop – look – listen – before approaching too close. In this specific case, the venting hydrocarbons were ablaze, but in some cases there is no fire, just an uncontrolled flow. The presence of high concentrations of hydrogen sulfide gas is always a consideration, even with oil blowouts as there is often a gas component to the reservoir fluid.”
Hydrogen Sulphide, H2S, dangers are well known to offshore workers and vessels servicing them are usually equipped with H2S meters and alarms but others, such as fishing vessels will not. H2S is characterised by a ‘rotten eggs’ smell but the gas itself can disable the sense of smell in higher concentrations.