BSAC Skill Development Courses

The first day was theory, long, but not too soporific. We received the theory books and tables. The lectures explained the, who, what, when, where, why and how. There ware lots of references towards the exam, highlighting points to remember. The theory pointed out that I did not have to go out and buy lots of new kit: bother, and Christmas just a few weeks away. The BSAC Nitrox tables made all the calculations very straightforward. The examples were chosen to make you think just a little bit more than blindly read off tables. We then went to the dive shop to play with the Oxygen analyser and collect our cylinders for the following day

The next day was practical, Stoney in November. The rain stopped and the clouds blew away, it was still cold!

Having assembled with the kit and retested the O2 percentage in the cylinder, we went diving. With a higher percentage of Oxygen there is a higher risk of O2 toxicity. This means with Nitrox there is a Maximum Operating Depth that must not be passed. Nitrox is not a gas for deep diving.

For the exercise we were set an MOD of 18m. On the helicopter 18m does not give you much to see, the tail and the top. The instructors kept trying to entice us lower; a few succumbed. We then tied of our SMBs and deployed them. Up to 9m to simulate decompression stops and to switch regulators simulating the use of a pony with a higher Nitrox concentration. Hanging around maintaining depth not that easy, and this was in still water. The stops were conducted horizontally. This is the preferred way to off gas as it keeps the whole body at the right depth; this is also how the tables are calculated. Up to 6m for even more switching. With not much swimming around you did start to get cold. Then out for 'Show and Tell' as to who got caught out by the instructors.

Lunch was taken with the multiple-choice exam. Not too hard, given the excellent hints/teaching the day before.

Cylinders were refilled, with double filtered air, reanalysed and back into the water for the next dive. Basically this was the same as the previous dive but with the added difficulty of launching the SMB mid water. Again no real problems nobody followed the SMB up or sank whilst deploying. Having got changed, it was into the bar for the debriefing (and a drink). All of us had passed.

I had attended the course only planning to only use Nitrox as a deco gas, but having attended the course I will now get one of my main cylinders O2 clean, if only for running training at Stoney.

On the way home I was less tired than normal, one of the perceived benefits of Nitrox, but I had also dived less than a normal Stoney visit.

What else did I get out of it: it was good to dive with others to see their configurations, and pick up some extra tips. All in all a good weekend well spent. I will be recommending it to other members of the club.

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We arrived, instructor plus 6 trainees. Instead of the usual left turn by the pylon, thru the gate, down a long and narrow dirt track to a grubby car cark and a further long walk to an admittedly rather picturesque little entry point hidden in the woods, we had a different entry method lined up for today. Today we would be boat diving in Littleton Lake, and making friends with the sailing club by hopefully finding some lost buoy mooring chains and more importantly their anchoring points.

We parked up first in the sailing club car park immediately upon entry. After making contact with a very pleasant lady by the name of Heidi, our sailing club contact, we proceeded to prepare for the day.

Before the usual business of putting scuba gear together etc, came the preparation for the day’s exercise, namely the practical part of our Search and Recovery course.

Preparation began with a discussion with Heidi’s husband who gave us details of where the missing chains were located, details of boats available to us for surface cover and the boat race times. There was mention of GPS positioning but I believe nothing came of this in the end. Rough position had been marked previously by a temporary shot.

Once the bigger of the available boats had been decided on to ferry us out there and an overall plan had been formed, we began on the dry run stage of the exercise.

The search pattern to be used was the Jackstay Search. The jackstay is a line, in our case 10 metres long, connected to the bottom of two shot lines. A base man would guide a line of diver’s perpendicular to the jackstay along its length.

We knotted ropes together plus a couple of floats and some of weights and laid it all out on the car park surface. It resembled the letter ‘H’ with the crosspiece almost at the bottom of the two verticals. The verticals were the shot lines and the crosspiece the jackstay. We then lined up in a right angle to the jackstay holding hands and slow-walked down the car park in a nice straight line being guided by the base man, emulating our search.

Of course, the reality couldn’t have been further from the truth – for true preparation we should have painted our masks black. Very thick black. Ear plugs too. But at least we had an approach.

Having stored the prepared ropes etc we moved the cars up to the very entrance of their clubhouse, kitted up and carted ourselves through the clubhouse to the grass overlooking the jetties to deposit ourselves plus kit over half the lawn. The sailing people were very nice; plenty of smiles from our occasional unobtrusive audience and all we spoke to were pleasant and helpful.

The lake suddenly looked quite big while looking out and contemplating our mission on the far side. Our boat for the day was a little diesel motorboat which was full with 4 sets of dive kit plus search rig piled in the bottom, four divers and coxswain. Two boat loads, instructor Andy Botten, myself, buddy Paul Lowry and Dave Whitlow as helper were on the first trip to the far side and the position of the lost number 7 chain, buddy pairs Pal Gray/Jane Woodward and Chris Hubert/Dave W followed in the second wave, the boat remaining as surface cover and return ferry.

There was a gentle breeze, just enough to need accounting for while positioning the boat for dropping the shots. Both shots were prepared to be jettisoned along with the connecting jackstay, weighted as it was by a small chain at its mid point. Aiming to place the midpoint of the jackstay close to the temporary marker buoy, the first shot was dropped over the side; the jackstay was let out as the boat motored up past the temporary buoy to the drop point of the second shot line.

This was where the fun began. Paul L and I were in first as it was our job to move one of the shots away from the other until the jackstay was straight and slightly tensioned. Due to the small size of the boat we entered the water with mask and fins only, bcd’s and weight belts were then handed down to us – never a bad idea to practice kit removal and replacement in-water in the pool. We then descended with Andy in attendance close by. It was Paul’s job to inflate the dsmb attached to the shot just enough to lift it and mine to man the dsmb dump valve in case he overcooked it. The lake bed was around 3.5 to 4.5 meters deep at this point and was covered in sparse weed rising to close to a metre, the bottom was part pebbly part black silt which resulted in complete blackout when disturbed. And I mean complete! In the end Paul waved me away through a clearish gap in the sooty fog and managed to move the shot by himself.

The rest of our search party had been instructed to give us a moment and then follow us down. I waited where I was, vaguely aware of the shot line close by as well as the chain of the temporary buoy which we had ended up right next to. Paul and I had lost contact though I knew he wasn’t more than a metre or so away from me.

I became aware of other divers, or at least small fragments of them would momentarily come into view – a piece of fin, an elbow, a glimpse of a tank. I carried on waiting, expecting to find Chris groping his way down the shot to find the beginning of the jackstay. He was elected base man and his arrival would be the signal to start forming our search line. As I waited I felt lightly around me with my fingertips. I’d already come across the jackstay, now I touched a solid feeling object in the shape of a large truncheon. As I felt my way along it I found a chain attached to it. Expecting this to be the shot of the temporary buoy I felt my way along it until it started rising up to the buoy above. When I looked down again someone else was going through the same motions. Yes it’s a chain, but no bananas, yet.

I waited a little more, slowly scanning about me for signs of life when a diver came into view and held out a fist with the thumb pointing up. ‘Good idea’ I thought, ‘this isn’t happening’. Up I went.

We regrouped on the surface, Chris took position next to the shot and the rest of us lined up, each holding on to the next diver along. Holding hands had been abandoned for obvious reasons, i.e. the need to control buoyancy, clear masks etc and importantly, allowing a free hand to search with, eyes were not exactly going to be much use. We descended in formation.

On the bottom, the signal was passed along to begin and we all moved off, in theory to conduct a sweep in a nice orderly line with Chris guiding us down the jackstay. In my position at the other end of the line I had moved what seemed to be no more than a couple of metres when the jackstay came into view a few inches in front of my face! Our line appeared to have rotated through 90 degrees. After a moment I moved off away from the line, still holding on to Paul’s bcd in the hope that our line was still intact, with the intention of pulling us out perpendicular to the jackstay again. We moved a little further forward, groping our way along the bottom in the blackness. Paul and I then stopped and looked at each other in another small window through the gloom. At the same moment we were both holding out the same signal – let’s ascend. Andy had already surfaced as had one of the other buddy pairs and a single diver, after a moment the final one broke surface. We had managed to loose formation and our line had broken up. This was proving to be anything but straightforward.

It was quickly and unanimously agreed that we were going to get no where in the abysmal vis and the decision was made to lift our search equipment lest that was also claimed by the lake’s dark depths. This operation at least was carried out successfully. Search equipment back on the boat, we decided to have a last attempt at searching for the chain, using an improvised compass search – we would spread out a little, descend in our buddy pairs and search along the same compass bearing, roughly indicated by Paul G’s “that way”.

I was in charge of the compass and Paul would hang onto my jacket, leaving each of us a free hand to search with. We slowly moved along the bottom, fingers feeling through the soft black silt. I lifted my head every couple of meters to get out of the blackness so I could check my bearing. After a few moments, to my surprise and pleasure I felt an excited tugging at my bcd. I turned around to have Paul hold up a length of chain to my mask – he had found it. He had actually found it!

We attached an improvised lifting bag to the end – a dsmb – and sent it up to the surface, following it up ourselves. We laughed “We’ve found it!” A buoy and line was thrown from the boat which was duly attached to the chain, the dsmb was removed and the chain sent back to the bottom, ready to be dealt with at a later date. Mission successful we de-kitted, exited the water and was ferried back to shore.

Back at the club house we spread ourselves out again and related our experiences. The general consensus was that communication was rather important while conducting such operations, that finger-tip searching was the only way to do it in such vis, and that that black gooey mess on the bottom was not only rather unpleasant to sift bare hands through, it also stank!

The sailing people were grateful to have had one of their lost chains and anchor points located and marked, and noises were made about having a go at finding the other missing chain and anchor point, as well as helping fix a new chain at buoy number 7.

All in all a good day, the weather was beautiful, we learned a lot about searching in extremely poor visibility and also made friends with our hosts at Littleton Lake. If you want to see how bad the vis actually was, Dave Whitlow has posted a video along with some photos of the day, these can be seen in the gallery section of our site in the 2009 section under Littleton Recovery 04 July. The shot line can be seen momentarily in the video, but then he descended…

Next time, my only wish is that we choose a Sunday, as this is the only day the bar is open. No point grumbling about the silt, Littleton is Littleton.

Happy diving,
Dave Moore

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