THE ONLY SURPRISING THING ABOUT DIVERS getting left behind by dive boats is that everyone seems to find it so surprising.
     Liveaboards are hotbeds of claustrophobia and suppressed rage, where intolerance breeds faster than MRSA bugs in an NHS operating suite.
     In a 1960s experiment, rats were confined in ever-more cramped conditions. They co-existed quite happily for a while - until their personal space was eroded beyond a certain, critical limit.
     Then they devoured their young, turned gay and fell upon each other with a terrifying ferocity - in that order.
     So perhaps the best way to exterminate rats would be to launch an intensive breeding programme.
     At any rate, the results should serve as a warning to every diver. Mollycoddle half a dozen in air-conditioned luxury aboard an ocean-going trimaran, and peace and harmony shall prevail. The balmy evenings will resound to good-natured banter and the tinkle of laughter, as the guests compete gently at backgammon and enjoy their Lionel Richie CDs on the quadraphonic sound system.
     But take your carefree punters, press-gang six more and squash them all below the decks of an old guano barge in the Gulf of Aqaba, and the backgammon board will be transformed into a killing field of hatred, blood and naked psychosis.
     The solution is to increase the space available to each diver by waiting until the least popular member of the party is 30m down, then hauling anchor and steaming, full speed ahead, for the horizon.
     Come on, we've all done it!
     Why, I recall that time off the Mewstone when Craig Dollop was so unbelievably bloody cheerful, despite the sleet and a Bovisand WMD breakfast, that his buddy was buying us all a beer ashore before Craig had even started his ascent.
     He was eventually washed up on the island of Sark, where he now combines the occupations of publican and stand-up comic. Sark is the most sparsely populated of the Channel Islands.
     Mind you, in my experience, the dive boot is often firmly on the other foot. I once spent 10 days on a liveaboard with a group of Welsh wreck-divers. Twice a day we would descend to 48m for three minutes - just long enough to attach the high-explosive charges to the propshaft of the Greek freighter Kleptomania.
     The rest of our time was spent in projectile-vomiting contests and renditions of Abide With Me in four-part harmony. I wouldn't have minded, but they made me sing the soprano part.
     There was only one thing for it: I gave my buddy the slip as she unseated the Kleptomania's boilers with her bare hands, then I hid beneath a heap of dangerously unstable mortar shells in the hold.
     To be fair, the Welsh did wait in case I surfaced. But after 30 seconds or so, they assumed the worst and chugged off. I surfaced to the strains of Men Of Harlech (the poorer, I felt, for the absence of the descant).
     It was with relief that I struck out for the coast of rebel-held Eritrea. As I kicked away a brace of over-curious tiger sharks, it occurred to me that Wales itself is rather like a liveaboard, where the "crew" are openly hostile and the paying guests quickly reduced to a state of simmering resentment, expressed in unpredictable outbursts of aggression.
     So you see, we're making a lot of fuss about divers getting separated from their boats. Yet in many cases, separation is the best thing for all concerned. At least it's more honest than staying together for the sake of the coastguards.