For the 1998 Worrell 1000, I purchased a relatively inexpensive set of EPIRBs for our team (Team Datek). We tested them immediately pre-race as per the instructions (tuned to the car's FM radio) and they worked fine. Early in the race, off the coast of Florida, we were caught in a severe thunderstorm, were dismasted and my crew became separated from the boat. We both activated our EPIRBs and I called the Coast Guard on the waterproof VHF radio. I was rescued within the hour but the CG was unable to find my crew. I spent an awful couple of hours before word came that he swam a couple of miles to shore and presented himself to the fire department that was searching for him.
It turns out we were quite close to a CG station but the range on the EPIRBs was so limited, the CG was unable to pick them up in the parking lot of the station.
Based on this experience, I wouldn't scrimp on safety equipment in the future.
Mike