Cargo door in the aircraft fuselage.

Its time to strap on a Megalodon and chill out in Somerset - John Liddiard finds that a training course provides a good chance to take in the sights

LOCATED BETWEEN RADSTOCK AND FROME in Somerset, I have dived in Vobster several times since my initial visit for DIVER just after the centre opened. Nevertheless, such visits have been for specific photographic projects, and each time I have stuck to a single location in the quarry that suited the job in hand.
I used the shallow training platforms to photograph drysuit inversions and mask removal. I spent hours on some shallow rocks at the far end to photograph finning techniques.
Most recently, I used the aeroplane wreck to give scale when photographing the yellow submarine.
What I had not done was actually to swim about and take time to see things, to see how the new attractions added since the dive centre opened fit between the existing quarry machinery.
An opportunity arises while I am training on a Megalodon rebreather with instructor Dennis Vessey. We had been planning to go to Plymouth and dive from the charter boat Maid Maggie, but the whims of summer weather soon put a stop to that. The forecast was a force 8 to 9 southerly gale with rain.
Vobster is quite well suited to such hostile weather, with the walls of the quarry providing shelter from the wind, especially mid-week, when there is ample parking by the dive centre at the waters edge.
The rain lets up as we arrive, then resumes as we finish preparing the Megalodon. I grab my drysuit and run for the shelter of the gazebo to change in comfort.
We enter the water by stepping off the quayside in front of the dive centre.
From here, a rocky wall drops to 15m, then we cross a ridge and descend a muddy slope that continues towards the centre of the quarry.

FROM A WARM SURFACE temperature, the thermocline by the bottom of the wall is particularly aggressive, dropping to below 10C in the space of a couple of metres.
By the time we pass 25m, the good shallow-water visibility has gone and the water is dark, silty and down to 8C. Im already wishing I had brought gloves.
At one point I lose track of the slope, then realise I have found it again when my face sinks into the mud. Dennis and I keep track of each other by torchlight.
The Megalodons head-up display provides a welcome reassurance of the ppO2 without having to check the handsets, both for me and for Dennis, who can keep an eye on it from over my shoulder.
The deepest point in Vobster is 40m, two-thirds of the way across. Its a mutual decision to give up navigating all the way there in these conditions, though considering my navigation on the way back, still without a compass, I am not sure I could have found the deepest point by any means other than a surface swim to the freedivers floating shed and down their line.
If I had checked the site map more carefully, I would have realised that there is a line laid under water to help divers navigate to the deep training platform at 36m.
To get cleaner and warmer water, we ascend a buoyline attached to a steel tank. By 14m my fingers are thawing out and visibility has picked up to 8m, perhaps a little more as the sun breaks through.
The Megalodon already feels like an old friend, but we pause and practise a few drills in midwater, maintaining neutral buoyancy while Dennis pulls out flash cards and I react accordingly.
On the way back to the quayside we divert to swim round the stone-loading pit, and then have a look in the blockhouse above. I am using Denniss rebreather while he dives open-circuit.
To get some pictures, I hand over my camera and pose while he clicks the shutter, which brings out another benefit of digital cameras. I set up the pictures by getting Dennis to pose, compose a picture, take a few shots to establish the right exposure and show him the results on the screen. Then we swap over and I repeat the pose while Dennis duplicates the picture I have just taken.
We could leave the water using conventional vertical ladders with rungs, the sort you need to take your fins off to climb, and which put a fair bit of weight on your arms when climbing with diving gear on. Being lazy, we end instead at the small slip, where it is far easier to pull fins off and walk up.
The sunshine is short-lived, the break in the clouds closes and the rain resumes with a vengeance. Having ordered egg and bacon rolls from the food van, we retire beneath the gazebo to keep the bread from getting soggy.

FOR A SECOND DIVE, we walk along a path at the side of the quarry to jump in round the corner by the shallow training platforms. The days ration of depth is already taken care of, so we can stay shallow and take it easy.
The 3 and 6m training platforms are scaffold and plank structures built on a rocky shelf at the side of the quarry.
It used to be the road to the stone-crushing works, and now provides
a useful perch for a fair bit of junk, a small boat between the platforms and the remains of dumped cars.
Silt that used to be a problem has been swept from the rocks by continued passage of divers. The shallow-water visibility is predictably clear.
At a depth of 12m, the quarrys largest added attraction is an HS748, a 58-seat twin turboprop passenger aircraft. Cut into sections for transport to Vobster, the two more interesting parts are conveniently located on the shelf.
First, we pass the forward section with the cockpit, then a few metres further on find the tail section, parked tail to nose. Specially for divers, the management has even left the toilet at the back of the cabin. The centre section of the fuselage is further along, past the quay.

OUT FROM THE TAIL section of the aircraft, a big green steel tombola standing in a frame is an industrial dryer. From here I cant resist a short diversion below the thermocline to the top of the stone-crushing works, part of the original quarry machinery before it flooded.
I admit it - given the opportunity, I am a wimp. We could have headed further below the thermocline to a larger boat wreck, but decide to stay shallow in the warmer and clearer water. Unless you need to go deep for a particular reason, staying shallow, as at many dive sites, is often the best dive.
For similar reasons, I decide to miss out on swimming through the tunnel that leads back towards the loading pit and the quayside.
We head over the rocks to the other end, rather than through it. The upper entrance to the tunnel is back in the warmer water and good visibility.
The clouds have parted and the sun is sparkling in the sky. It almost feels like summer.

Entry fees to Vobster Quay are 10 for members, 15 for non-members. Membership costs 25. Full details,

The Megalodon is a full electronic-control closed-circuit rebreather (CCR).
The control system is enclosed with a three-hour scrubber in a back-mounted canister, with wrist-mounted controller and back-up monitors and a flashing LED head-up display by the mouthpiece.
Cordura or optional neoprene counterlungs fit over the shoulders, as with an APD Inspiration, though the breathing loop flows in the opposite direction, so some of the drills are necessarily different.
Oxygen and diluent cylinders are mounted externally either side of the canister, so cylinder size is not restricted by any outer casing.
A simplified option is the Megalodon Copis, in which the electronic control package is replaced with a constant mass flow system and basic ppO2 meters.
Expect to pay upwards of 4075 depending on options and exchange rates. The Megalodon is scheduled for CE-approval testing.
Training and service: Manufacturer:
The water at Vobster looks quite welcoming in the sunshine.
Always a source of fascination for divers, this flooded toilet in the aircraft is no exception.
The controller and back-up electronics for the Megalodon are separately encapsulated within the canister lid.
A gazebo makes a shelter for kitting-up out of the rain.
The aircraft fuselage has been cut into sections, making the inside safely accessible
window in the aircraft fuselage
an industrial dryer.
Burgers, bacon rolls and everything else that divers must have between dives.