Today I was out diving and heard on the radio that the Narcosis Dive charter out of West Palm Beach reported a lost diver. We listened on the radio for quite a while. The dive boat was searching for the diver, it sounded like other charter boats were also looking on the surface. The police helicopter was searching the surface and the USCG had at least one vessel deployed in the search. The police helo left the scene after many passes and the CG helo was enroute after the other aircraft left. Conditions today were PERFECT less than 1 foot seas all morning and about a 1.5-2 kt current on the surface, winds were probably less than 5 mph. After a few hours, it sounded like the dive boats were assuming the worst and began doing underwater sweeps (obviously with the intent of making a body recovery). I think at least one private vessel was deploying divers to search as well. We were diving offshore of the scene and could see the boats and helo etc. After being lost for hours, I was pretty sure that the diver was dead, because the surface conditions were super calm, clear skies, and no restriction on visibility. I figured there is absolutely no way a diver could have gotten away from a charter boat on a recreational drift dive (I think the depth was 75 ft or so), to the extent that even a helicopter could not spot him. I was making my way over to the scene, the Narcosis boat was dropping more divers and they sounded like they were appreciative of any help with searching of the bottom by other boats. I was preparing to do a dive and sweep the area, when we heard on the radio that the lost diver had actually made it to MacArthur Beach Park and had walked up on the beach and made a phone call from there! Thank GOD. That is incredible, the distance is roughly 3 miles north (down current) from the dive site and the diver must have swam in (across the current) a distance of close to a mile (rough estimates). Does anybody know what the story is? It is absolutely amazing to me that the diver's drift pattern was apparently not predicted accurately and that he wasn't spotted on the surface under these ideal conditions this morning. How does somebody get lost on the surface, in perfect conditions, for apparently hours and nobody is looking in the right place for him?