“DO NOT follow me. I am going to the main airlock.” For what reason? “I do not know.” Bet you do really. “I will tell you later.” So ran the acquatic antics of half-man, half-fish Mark Harris (PATRICK DUFFY), about whom a voiceover was always at pains to point out: “Childer-en are warned not to attempt to copy Mark Harris”. And so we did, either the silly hands-by-sides underwater bodypopping swimming stroke (difficult – tendency to sink like a stone), the having gills and webbed hands (very difficult) or the sleeping in a bath full of water (easy but dangerous). BELINDA J. MONTGOMERY bankrolled him at the Foundation for Oceanic Research. The Cetacean was the name of the submarine which drove Mark around the sea bed. A bit pointless, seeing as he could walk it anyway.