The shipwreck of a luxury yacht moored off the coast of Sicily is the latest sign that the Mediterranean is becoming a more dangerous sea to sail in, climate experts and skippers say.One man died and six people are still missing, including British tech entrepreneur Mike Lynch, after the Bayesian, a 56-metre-long (184-ft) sailboat, was hit by a ferocious storm on Monday, sinking in a matter of minutes.Climatologists say global warming is making such violent and unexpected tempests more frequent in a sea used as a summer playground for millions of tourists…