For many of us, prime boating season is about to begin. There will be searches for missing boats, people lost overboard, etc. Here is an interesting article on how the USCG decides to suspend a search:

Giving Up: Why the Coast Guard quits looking

When the Coast Guard suspends a search for a missing boater, hearts that were breaking already fully break and the news is met with more than just tears; there is often also anger, confusion. That anger canít be helped, but the confusion can be. Most people lost at sea stay lost. Itís a harsh reality that the USCG deals with every day. So when the Coast Guard suspends a search, they arenít ever giving up early.
To me, the most remarkable thing about the PSDA and how the USCG makes decisions about search times is the extraordinary benefit of the doubt they give to persons in the water without a life jacket.

Note that Mario Vittone is a retired USCG Rescue Swimmer. He was also one of the subjects in the "Cold Water Boot Camp" videos that came out a few years ago.
"Toto, I've a feeling we're not in Kansas any more."
-Dorothy, in The Wizard of Oz