The Master's Legal Duty
The duty to render assistance sits with the Master personally. Under SOLAS V/33, on receiving information from any source that persons are in distress at sea, the Master is obliged to proceed with all speed to render assistance. This is not a discretionary act — it is a legal obligation under both SOLAS and domestic law. If the Master decides not to proceed, the reasons must be recorded in the Official Log Book. The threshold is any source: a DSC alert, a VHF relay, a visual sighting, or a report from a crew member all trigger the duty equally.
Initial Actions on Receiving a Distress Signal
Acknowledge receipt on the frequency received, then assess. Plot the position immediately — this establishes ETA and allows the Master to make an informed report to the MRCC. Inform the MRCC (or the coordinating SAR authority) at the earliest opportunity, because they will either task you formally as On-Scene Commander (OSC) or release you to proceed to your destination if a more suitable vessel is closer. Do not self-deploy and then go silent; maintain a communications schedule with the MRCC throughout.
Brief the crew and bring the vessel to a higher state of readiness: survival craft ready for deployment, first-aid team and equipment mustered, recovery equipment prepared. The reason is that the situation may deteriorate rapidly once on scene — time spent preparing en route is time saved when survivors are in the water.
Approach and On-Scene Assessment
Approach the casualty upwind and up-current initially, then manoeuvre so survivors are recovered from the leeward side — this gives a lee for survivors in the water and prevents the vessel being set down onto a casualty vessel or wreckage. In open water, consider the wind-over-tide effect on your vessel's leeway; a yacht under windage will drift faster than a semi-submerged survivor.
For a vessel casualty, establish communication, assess whether evacuation or tow is the priority, and confirm whether fire, flooding, or structural failure makes it unsafe to go alongside. For an aircraft ditching, mark the position (survivors disperse quickly), keep a good lookout for life-rafts and EPIRBs, and watch for fuel on the water — flash point considerations apply to recovery boat deployment.
Rescue Execution
Deploy a rescue boat if conditions and your crew competence allow — direct recovery from a yacht's deck in any sea state carries risk of losing crew. Use a throwing line or rescue quoit first; only put persons in the water if absolutely necessary. Hypothermia affects a survivor's ability to grip or climb, so rigged scramble nets, a dinghy, or a man-overboard recovery sling are preferable to a ladder. Once recovered, apply HELP position principles, manage hypothermia, and document each survivor's condition.
Post-Recovery
Inform the MRCC of numbers recovered, their condition, and your intentions. If survivors require medical care beyond your capability, request medevac. Log all times, positions, actions, and decisions in the Official Log Book — this record is evidence of compliance with the legal duty.