LEEWARD

Firstly – when using sails, the winds will carry you further
away from the island and hopefully across shipping lanes…

 More obscurely – substantial island land-mass elevation
causes “open sky” patches only on the leeward sides…

 …air based reconnaissance and rescue has a much better chance of visually spotting you…

Satellite Image: Wave Clouds and Vortices Aleutian Islands: Bering Sea

Gatfol can be life-saving !