Buoyancy and Trim & Accelerated Decompression Procedures

Geraint and Daniel spent a lovely day at Wraysbury on the Buoyancy and Trim workshop and in North Cornwall on the Accelerated Decompression Procedures Course.  Here is their account of these regional courses.


The day started with a briefing and a set of lectures around the importance of buoyancy control and how the general principles can be applied as well as some commentary about the impact of good trim.

Our first of two dives was an experiment dive where we could fiddle with weighting and trim and practice some of the skills before the assessment. We navigated a maze while maintaining good buoyancy, hovering parallel with a feature under the water and then slowly ascending with a stop of at least two minutes at every meter from 6m to 1m and then one final stop at half a meter.

The second dive was an assessed version of the first dive and Geraint and I did a great job of maintaining our buoyancy all the way up and doing various skills at each stop like spinning on the spot, mask clearing and attitude adjustments. This was later confirmed when our instructor awarded us both “Black” for Buoyancy and Trim.



Isuffering-with-finger-injuryt was held in North Cornwall not far from Rock and started in a nearby boat yard on Saturday morning.  Our Instructor, Mark, started by running us through some of the theory associated with the Twinset course and the ADP course. He was very clear about teaching “the BSAC way” and what pragmatic alterations we could make after training.

The first dive was a 6 m skills dive where we went through mask clearing, spare mask replacement, valve shut-off procedures, reg-switching for the deco stage, air sharing with long hose etc.

The second dive was in 23 m of water on a wreck. The vis was atrocious so we all lined off.  We didn’t do a deco dive as we ascended before the no stop limit but we still simulated swapping to 80% mixes at 9m and switching gasses on our computers.

Mark had an incident on the dive which resulted in a severe cut to his finger so he was taken to Truro hospital for stitches. While we waited the three of us went through the manual process of planning an accelerated deco dive using the tables and the materials we’d been given the previous night. Mark eventually came back about 10 o’clock, completed the lectures for the course and we finished about midnight!

On the Sunday we buddied up and dived our plan on the Indus – a wreck at about 45 m but as we’d planned for 40 m we were hovering above it – plan the dive and dive the plan! The wreck was fantastic and I wish I’d had more time on it. I had no problems switching gasses on the way up and we did our accelerated deco.

Back at the boat yard we unloaded the boat together, got de-kitted and loaded the cars. I was able to sign off dive management for Dive Leader as well as the ADP and Twinset SDCs.  Geraint and I are both Advanced Twinset divers!

We would recommend both these courses to anyone thinking about doing more decompression diving. I am very pleased that we will be able to practice our Accelerated Decompression on my next dive trip to Scapa Flow.

Examination Success

Please give your congratulations to our newest Open Water Instructor.  Very well done to Sally.


Becoming an Open Water Instructor requires the diver to pass a classroom teaching exam, an open water teaching exam and a knowledge exam.  It also takes years of hard work.

Plymouth – 27th-29th August 2016

With fine weather two of the three days all six planned dives were successfully completed by various combinations of those present. We dived from the Explorer on all occasions and by all accounts it was very easy diving.

Victor and I headed down early Friday to avoid the traffic, stopping only once for breakfast at Gordano services. A relaxing afternoon spent around Mount Batten and back at the B&B waiting for the others to arrive. We met people in various pubs and then headed out to the Mount Batten bar for dinner.

Saturday saw us dive two wrecks (the Scylla and the James Eagan Layne) in fabulous weather – blue skies and calm water. Visibility was good both dives (6 – 8 m, if not slightly more). Plenty of life on both and I found the wrecks interesting to swim around in their own right. I saw my first box jellyfish. When I pointed it out to my buddy Clare, a friend of the club from Ipswich, she seemed very unmoved by it. It later transpired that she’d seen many of those and didn’t realise it was my first. On the second dive, she pointed several out to me – that made me smile.


Rolling backwards off the side of Explorer was the entry mechanic which, while awkward at times, seemed to work OK for most people. A couple of times my head hit the water first which caused a jolt but otherwise fairly painless. Others weren’t so fortunate with a back injury exacerbated by the manoeuvre.

Saturday evening we went to the Glassblowing House for dinner. A fabulous meal that seemed to be enjoyed by all present. The food was of good quality and there was a range of options available on the menu.

Sunday brought a combination of sickness from our fearless leader, Victor, and some bad weather. The wind meant we couldn’t dive outside the harbour so a couple of spots were chosen inside for those of us willing to partake.

While the visibility was lower inside the harbour (3-4 m most of the time) the dives were still fun. Ken and I saw a few notable highlights across the two dives, including cuttlefish and what looked like a pipefish. Visibility around the Breakwater Fort (the second dive site of the day) got challenging in a few places where, it looked like, several trainees from other boats were getting anxious near the bed. I can empathise entirely with their predicament having struggled with buoyancy for most of my diving career! By coming a little shallow and keeping the fort wall at arms length we were able to come out the other side unscathed.

Bank Holiday Monday brought the return of fabulous warm, sunny skies and calm waters; though not calm enough for some (*cough* Xin *cough*). I jumped in with Teresa and Emma for the first dive around a wreck (Le Poulmic) that was teeming with marine life. I saw some crabs, a couple of lobsters and a few other critters in the crevices of the wreck itself. While shoals of fish patrolled the outer edges making swimming in the surge look effortless. I felt sorry for Emma – the surge of the water meant that I kept bumping into her fins (when I wasn’t bumping into the wreck of the surrounding reef).

The second dive on the Monday was another wreck apparently (the Glen Strath Allan). Emma and I went down the shotline to find a lobster pot tied to the end of it, instead of a large boiler. Still, S-drill complete, we had a lovely dive around a reef. Saw a few box jellyfish, the odd crab and few small fish among the kelp forests.

All in all a very successful trip. On returning home I noticed that we had traveled down on a third of a fuel tank, back on a third of a tank leaving a third reserved. Perfect!

2nd Post

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