I found RustyNail's response fascinating, so did some reading, and found some interesting information on just how unlikely things are without a 406 MHz DF capable SAR effort.
This is from the USCG account of the F/V Extractor, with a non-GPS 406 MHz EPIRB
On 12 Jun 05, 10 separate aircraft, 18 sorties, 19 search areas, and 13,118 sq. miles were expended to locate the 34’ P/C Extractor 26 miles off the coast of Florida. After thousands of miles of cumulative search effort, CG 1504 launched from Elizabeth City, NC (with a DF-430-F prototype on board) en-route to the assigned datum. While still 90 NM from scene, at 17,000 feet, the DF-430-F locked onto a 406 MHz ELT signal. The C-130H Hercules crew flew directly to the new electronic intercept solution and located two hypothermic survivors clinging to the bottom of an overturned craft, thus ending a 20 + hour search. An HH-65 was vectored to the position and hoisted the two survivors to safety. These two survivors had been holding onto the bottom of the boat for over 24 hours.
What I find fascinating about this is that even though the boat had an EPIRB that was activated, since it did not have a GPS the CG still had to search, covered 13,000 square miles, and still didn't find the vessel. Only after an aircraft equipped with a prototype 406 Mhz DF set was dispatched was the vessel found. This case was used to bolster the argument for installation
of 406 MHz DF equipment
throughout the CG fleet.
And this from a DF search for a vessel with a GPS enabled EPIRB:
As we got closer, it was apparent that the DF was pointing a few miles away from the GPS coordinates passed by the Sector...probably due to normal drift - wind/current. We went strait to the where DF needle was pointing us.
So, the GPS position gets stale quickly (CG stats say about 30% of GPS EPIRBs successfully report a position).