Here's a possible scenario...

He's out there to scatter his mother's ashes. The wind and seas are
relatively calm, so he's likely running on the engine. Perhaps he has the
autohelm driving. Even sunny, it's pretty cold right now, and with the
moving boat, he's definitely wearing a foulie or something for a wind break.
Since he's a careful sailor, according to all the reports, he's definitely
wearing a PFD is likely tethered to the boat. I would be if single-handing
offshore. (I do that in the bay when by myself on a typical day of 15 to 20
kts.)

He has some sort of catestrophic medical event.. HA, stroke, whatever, and
dies or is incapacitated quickly, unable to summon help. The boat continues
under autopilot at say 7 kts. If this happened at 10 nm offshore, about the
max range of a cell phone in that area, and he wasn't reported missing until
20:30 hours, then when they finally started looking say at 22:00, he would
have been 20 x 7 = 140 nm. It would take them several more hours to search
this far out, so he might be 200 nm off. The boat would have something like
40 gals max. So, at 5 miles per gallon (SWAG) that would be 200 nm until the
engine died, but if sails were up, it would still be going. Perhaps he was
able to sail for part of the trip. If so, that would extend the range. The
winds were light, under 10 kts, but that's still enough to make good
progress.

--
"j" ganz @@
www.sailnow.com