Lifeguard Duty

I'm having problems in completing this mission and I'm having no joy with the threads already started regarding this rather annoying mission I have arrived at the icon and after a day or so crash diving etc to evade enemy planes I'm beginning to loose interest in this one. I have to remain on station by Feb 17th and it's Jan 21st, am I too early? or does arriving at the icon trigger the mission? Also, I read about currents etc. do I just patrol randomly in the hope of finding the pilots?

Please help!