I have been puzzling over the strange story of David Sharp, the 34-year-old British climber who died on Mt Everest last month. As many as 40 other climbers saw him in distress and left him to his fate as they made their way to the summit.

Although some did try to help him, it is hardly surprising that this potentially avoidable death has generated controversy. Every mountaineer knows that the only way to save those in such a position is to move them as quickly as possible to a lower altitude. Sir Edmund Hillary, who conquered Everest in 1953, said it was "horrifying" to think of climbers leaving a man to die simply to pursue their own ambitions of reaching the top. Sharp's death was given added poignancy because Lincoln Hall, a 50-year-old Australian also left for dead on Everest 10 days later, was subsequently rescued and restored to health.

You may wonder what any of this has to do with sailing, but the two activities have much in common. Many mountaineers take up yachting when they can no longer manage the climbs of their youth. Bill Tilman, who disappeared at sea somewhere between Rio de Janeiro and the Falklands in 1977, was famous for his exploits as both mountaineer and sailor.

Perhaps it is just that practitioners of the two sports share a perverse pleasure in getting cold and wet, banging their heads and crushing their fingers, eating packaged food in awkward, cramped positions and seeing how much strain a high-tech piece of rope can really take. One of my crew on a passage across Biscay used his mountaineering connections to obtain for our Atlantic cruise all kinds of medical supplies that would normally require a prescription - including powerful antibiotics and tranquillisers to subdue crazed members of the crew (happily never used.)

Sharp's death, however, revealed what seems to me a fundamental ethical difference between sailing and climbing. I cannot imagine any sailor knowingly leaving another to die if there was the slightest chance of effecting a rescue - regardless of hardship and difficulty, let alone one's personal ambitions or position in a race. Those Everest climbers who passed Sharp, remember, were not on their way down from the summit, but on their way up with reserves of oxygen and personal energy.

Clearly there are times when it is physically impossible to save another person. Who can condemn the mountaineer Simon Yates for his agonised decision in the Andes to cut the rope binding him to his injured partner Joe Simpson? Cutting the rope sent Simpson tumbling to what seemed like certain death, but it was the only way Yates could extricate himself; one death is better than two. In the event, Simpson lived to tell the tale, immortalised in the book and film Touching the Void. At sea, there have likewise been many occasions when sailors close enough to rescue someone in trouble are themselves fighting for survival and therefore unable to help.

But it is completely routine for sailors to sacrifice their chances of winning a race, and even put themselves in danger, in order to save others. Only last month, when Dutch crewman Hans Horrevoets was washed overboard into the Atlantic from ABN Amro Two during the Volvo Ocean Race, others competing boats immediately changed course to assist in the search. As it happened, the crew of ABN Amro Two quickly found Horrevoets, but he was already dead.

Probably the most extraordinary sea rescue of recent times is the saving of Raphaël Dinelli by Pete Goss in the 1996-97 Vendée Globe single-handed round- the-world race. Goss turned back on Christmas Day 1996 to beat into a Southern Ocean storm and save Dinelli from certain death - a feat that earned him the Légion d'Honneur and a firm friendship with Dinelli.

Sharp's fate on Everest suggests that some mountaineers would have had no compunction in leaving Dinelli behind as his boat sank in the frigid Antarctic waters. Luckily, Goss did not take the mountaineers' view - let us hope it is a minority view - that Dinelli was probably finished and therefore not worth trying to save.

And yet Goss did not really have a choice. Most sailors assume there is an unbreakable rule that obliges them to go to the rescue of someone in trouble, and even if there is no law to that effect the tradition is deeply entrenched in sailing culture. Not every rescue attempt will succeed, but if you hear a cry for help from those in peril on the sea there is no question that you are obliged to try.

victor.mallet@ft.com

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Tim Yeo's golf column will appear next week