There is a thread on PLB's here but no talk of SAR systems which I have always leaned towards.... they used to be prohibitively expensive but changing technology is making personal SAR systems much more accessible.... one that has caught my eye is the Kannad Safelink R10. Never used one but reads like a great piece of gear.
Kannad SafeLink R10 SRS AIS
The advantage of these of course striking me as if someone goes over your AIS will show you where they are as long as they are in range (4 miles or so) where as with a PLB you would have to have a way to talk to a coastal authority to have them tell you where the person is and then try to find them...
Anyone here have experience with any of the new AIS based SAR systems?