Tidal Thames.qxd 9/24/07 2:22 PM Page 8

n the bottom Thames Estuary. As commercial diving a falling tide, but leave them the diver, a stand-by diver and a Kevin said: “She gives us a large of the He rarely knows what goes, the PLA team doesn’t vulnerable on rising tides. So tender or dive assistant. deck area to work on and her speed’s Thames, the day will hold or, once go deep - typically around everything we do has to be timed They can dive from any vessel; very important. In an emergency we Mick he’s under the water, what eight to 20 metres. But poor precisely, according to where in the but they prefer to use their own may only have a narrow tidal window Russell is will loom out of the visibility and shifting river we’re expected to work.” specially designed boat PLA Diver. It to work in, if we miss it, we could be blind. darkness - driftwood, currents in some of the The divers get their jobs from was built in 1992 by Searle Williams waiting up to 11 hours before the The water’s disturbed wartime busiest port waters in either the PLA’s Marine Services team, on a Blyth 33 hull. At 10 metres long conditions are right again - so it’s thick with silt and, just a explosives, the occasional Britain, makes the Thames a Vessel Traffic Services (VTS) officers, and with a displacement of seven vital we get on scene quickly.” few inches from where he’s corpse. challenge. or from the authority’s Hydrographic tonnes, she’s capable of speeds of Back on the river above the standing, there’s total Many of the PLA divers Department. around 20 knots. petrified tree, Mick emerges from Mick Russell darkness. have a military background; Diver Peter Semple said: “VTS coffee-coloured water. He can’t move all are put through rigorous will call us if a ship fouls its “It’s not the most easily - he’s carrying training and repeatedly propeller. glamorous job in the It’s not weights; the riverbed’s assessed throughout their “But we get most of our work world,” he says. “And the most treacherous under foot; working lives. As a result, from Hydrographic. They’ll give us it’s not the highest glamorous and, although the high each one knows the river details and coordinates for anything profile because the tide’s almost on slack like the back of his hand. they find when they’re surveying the river community job in the water, the remaining Kevin Leadbetter, the river bed. can’t see us in world, and it’s current’s still strong PLA’s Diving Supervisor, “Then it’s a case of anchoring at action, but we’re not the highest enough to buffet him. said: “It may be one river, that location and lowering a diver always closer than It’s cold, bitter cold - but the Thames has very down the anchor chain. On the they think.” profile because just three or four degrees. different characteristics bottom, he’ll attach a line to the the river The mask of his Kirby depending on when and anchor and swim or walk in a circle community Morgan dive helmet has where you dive. around it until the line catches on “We always work can’t see us in already misted over. the object we’re looking for - it’s But Mick is used to it around low or high water, called a snag search. action, but - as one of nine Port of when the current’s at its “It’s a very effective way of we’re always London Authority divers, slowest. But near finding objects in poor visibility, closer than he spends most of his Richmond the current is and it’s rare that we come back working days like this. In always quite noticeable empty-handed.” they think fact, the soundtrack to because the river’s natural Any diving has its dangers - his life is churning water; flow takes over when the the bends or burst lung are his own bubbling breathing; Mick said: “You tide slows down. probably the most widely and the distant high pitch wouldn’t believe a lot of the “In central London, the known. But commercial divers mosquito buzz of boat stuff we find - a WWII bridge piers cause unnatural also run a greater risk of propellers above him. German fighter plane eddies and whirlpools. At being trapped. And they can Today he’s looking for a engine, even an Elizabethan Gravesend, the river bed is face ‘blow-back’ - an petrified tree that’s shipwreck. very muddy and visibility’s explosion caused by gas appeared in the shifting “Some of the lads dived extremely poor. And, from trapped during underwater mud of a dredged channel. on what we thought was a Southend to the North Sea, burning. Tomorrow he could be generator in the Thames the bottom’s pretty much Peter said: “The force of it inspecting lock gates at Estuary, but when we got it sand, so visibility gets can damage your regulator - the Richmond, recovering a to the surface we realised it better but you’re exposed to bit that feeds air into your sunken barge at was a mine. the full force of the sea. helmet - and when this happens, Westminster, securing “The problem is we “Because of the river’s your headgear fills with water and moorings at Greenwich, or can’t see what we’re dealing shape, there are certain you lose surface communication.” freeing a ship’s propeller with while it’s on the bottom sections that shelter divers To reduce risk, PLA divers work from fishing nets in the - we have to work by touch.” from the currents caused by in teams of four - a dive supervisor,