A MAN WATCHES SILENTLY as, across the gently rippling water of a Clyde bathed in brilliant August sunshine, the hills and mountains of Scotlands west coast cast a shadow. A hundred metres below, technical divers are unlocking the secrets of the last moments of HMS Vandal, a submarine lost with all hands during World War Two.
     The past 60 years have troubled Larry Gaines, who is standing waiting for the divers to return. When Vandal was lost, he should have been on board. Instead, he was laid up in the sick bay with an ear infection, and replaced by a younger, inexperienced stoker.
     It was Gaines job to secure the aft engine-room hatch and he has always blamed himself for Vandals loss.
     The members of the diving team have several objectives. They want to identify the site positively as that of Vandal, and they want to try to answer the questions that remain about her loss, including the one that has haunted Gaines all these years. The team will be the final jury in the Vandal affair.
     This is a very different kind of project, a series of sensitive dives designed to reveal the truth before Vandal is designated a war grave by the British authorities.
     The divers will have to act quickly, because they will never be allowed to dive the site again after the designation.
     On 22 February, 1943, Vandal was on a three-day exercise programme of simulated war conditions. Captain Lt James Bridger was preparing his newly assigned crew before going on active patrol. But Vandal never returned from the exercise - she disappeared with her crew of 37 officers and men. What had happened
     Sixty years later, two British divers who are partners in life and diving alike, Nick Gilbert and Adina Ochert, have assembled a team of deep technical divers to solve the mystery. For years they have delved into the archives for clues to Vandals loss, and with the consent of Larry Gaines and the families of those lost they intend to carry out a full analysis of the wreck thought to be that of Vandal.
     HMS Hurworth discovered this wreck in 1995 after the Scottish branch of the Submariners Association persuaded the Navy to search an area where trawler nets had reported being snagged. Cameras from an ROV later confirmed the site as that of a British submarine regarded as Vandal, but the images were of poor quality and, if this was Vandal, there was still no clue as to what had happened to her.
     Each diver has been assigned to use his or her own skills to find the answers. My task and that of the videographers is to pinpoint and record how the loss occurred, in my case on 35mm film.
     The Clyde is not the most glamorous place to go diving, and neither is it renowned for its visibility.
     The descent to Vandal is like no other. Nature is quick to shut her light out, and any rumours of visibility are soon corrected as my torch beam picks out no more than 2m below me.
     Im alone. I know that the only images I will capture, if any, will be close-ups, because I wont be able to frame a diver as well. I can think of no better or more insane excuse for being at the bottom of the Clyde on my own!
     Nick and Adina are the first people to touch down on the Vandal since the day she was lost. They make an excellent job of securing a line to a strong section of attack periscope.
     The wreck rests in pitch darkness on a muddy slope in exactly 100m of cold water, with a 35 list to port, lying in the same attitude as the slope.
     My rebreather loop contains 8/60 trimix (8% oxygen, 60% helium), mixed to give me the benefit of diving to an equivalent depth of just 35m.
     After a change in setpoint the oxygen cells settle, and Im happy to move on steadily and orientate myself.
     Having been involved in the exploration of other significant Naval submarines, I have expected to be well up to completing the job in a single dive, but I soon realise that this wont be the case. Trying to make head or tail of any damage across large areas will be difficult in this visibility although, moving deeper, I can see that the conning tower is no longer in its original state.
     With the absence of narcosis I can make mental notes of my route and the direction Ill need to take to re-locate the line to the surface. I find the muddy seabed, where sections of the conning tower have either collapsed or been broken off by snagged trawl-nets.
     To identify the wreck, a close examination of her design should be sufficient, but ideal would be to find the name.
     A small ladder comes into view, my torch beam picking it out rung by rung. This would have allowed the men to climb down from the tower onto the pressure hull.
     The ladder leads to what was the top of the tower, but which now lies at a right angle, somewhat twisted.
     Then I see a large letter L!
     As I follow the top of the conning tower along, the entire name Vandal, in classic naval brass letters, comes into view. We have positive ID on day one.
     This area of the wreck will need the lens of the video, and as I begin to terminate my dive I flash a light beam to a nearby pair, who move in to film what I have just found.
     My VR3 dive computer indicates the time I have left before I reach the surface, and the backlight Ive programmed to stay on comes into its own on such dives.
     It will be some time before I leave the darkness, even in my deco phase.
     As we break the surface after a lengthy decompression, skipper Jim Queen awaits aboard his dive charter mv Spinaway Isle. Queen has contributed hugely to this project. During the build-up he spent hours searching for the wreck, after the official position turned out to be nothing more than a 76m bare seabed! Spinaway Isle proves to be the perfect platform from which to work, and Queens enthusiasm for the project blends well with that of the team.
     Each night the video teams of Kevin Pickering and Chris Hutchison run through their film with Larry Gaines. Bryan Thomas and Sandy Young of the Submariners Association join us, and are equally thrilled to see for the first time good-quality digital film of HMS Vandal.
     After the second day, with a clearer picture of the wreck emerging, the divers are in a position to discuss evidence surrounding Vandals final fatal moments. Nick Gilbert gathers the team and begins to match clues from the film against his build plans of the boat.
     His knowledge of U-class submarines and high level of research are clear as he guides us through what he believes happened to the Vandal.
     Larry Gaines is smiling. The divers have informed him that the aft engine-room hatch, the one he believed his less-experienced replacement might have failed to secure, has been found closed.
     The 12lb gun remains on its pedestal forward of the tower, covered in trawl-net, so that all that is visible is the pedestal base.
     As the video shows, the team has reached both the bow and stern and filmed the entire pressure hull. At the very stern a 1.25m section known as the ducks tail is missing, but it is not part of the pressure hull or a reason for the sinking. The divers also identify scuffing on the starboard propeller tips, which could indicate that the engines were run in an attempt to drive the submarine off the seabed.
     Approaching the bow section, the divers are confronted by the forward escape hatch - wide open! It appears to have been opened from the inside, and peering inside reveals no ladder in situ.
     The grim significance of this find adds to the existing evidence of what may have happened.
     Some of the outer plating has rotted away from the bow, revealing more of the torpedo tubes and the torpedo-loading hatches, both clearly closed. Divers Steve Parker and Guy Middleton report seeing the boats hydroplanes in the stowed position, yet another clue.
     As the project comes to a close, one last dive remains. All but two of the team are closed-circuit divers and all are keen to see for the last time the key features. As a layer of light silt covers the wreck, each diver is careful not to reduce the visibility any further.
     It is on this final dive that the ultimate clue is revealed. Photographs and film both show manila rope still neatly stowed about the ships mooring bollards.
     This discovery takes on significance when Nick and Adina later approach submarine experts, including an official from the Marine Accident Investigation Branch of the Department of Transport, two retired U-class submarine commanders and several ex-submariners. All of them state confidently that the sub would not have dived under any circumstances with the rope still lashed around bollards.
     Submarine mooring lines are always taken for stowage below before a dive, and that indicates that Vandal was lost not during a dive, but from the surface.
     We now have a strong theory about what happened. The area in which Vandal lies, known as Quebec, is still used today by submarines to perform log calibrations over a measured mile.
     Vandal would have sailed in a straight line between two transit points and performed the calibration at the surface.
     She was last seen at the surface around 10am. Some of the crew may have been raising the log to perform maintenance or rectify a defect. The log was a watertight container that was lowered through a hole in the bottom of the boat. The flow of water past the transducer it contained would drive a small impeller to give an electrical signal proportional to the speed of the boat.
     To raise or remove the log, it would be retracted into its tank and the sluice closed to seal the opening. The log tank could then be opened to remove the transducer.
     This was always considered a hazardous activity, and was the main contributing factor in the loss of Vandals sister-ship HMS Untamed three months later. If the sluice jammed against the transducer, which was still protruding through the bottom, and the log tank opened, seawater could rush in at a rate of 2 tonnes per minute.
     In this situation the compartment would have been evacuated and sealed using the watertight bulkhead door to the rear of the torpedo stowage. However, it seems that a number of ratings were trapped in the compartment (also used for accommodation). As alarm took hold, some may have tried to save themselves, while the boat was still on the surface, by opening the forward escape hatch.
     This hatch had been found fully open, and the absence of a ladder leading up to it could indicate that it was opened in a hurry, causing further problems.
     With the hatch open, the supply of compressed air would have become ineffective, leading to unchecked flooding of the compartment finally taking the boat to the seabed.
     HMS Vandal may never see another visiting diver, but it no longer needs to. We believe we know what happened that day - and Larry Gaines no longer needs to feel any sense of responsibility.
     Further detailed information about the Vandal project can be found on the website.www.deepimage.co.uk

Larry Gaines, sole survivor of the Vandal, pays tribute to his friends
one of the team, Christina Campbell, examines the attack periscope
Brass letters on the conning tower display the name Vandal
at almost seabed level this compass remains attached to the conning tower
a small ladder which once made its way up the conning tower
the forward escape hatch, wide open!
divers of the Vandal Expedition
Jim Queen, skipper of Spinaway Isle, mixes gas