Category Archives: Drysuit

AOW, 27/28 April 2013

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A very intense weekend comprising one day at Wraysbury and one further afield at Vobster Quay, my first time at the latter (as I have mainly dived in the sea). I was very impressed by Vobster, it is much better equipped and run than many “real” dive operations. The group comprised instructor AD, DM GL, 5 students and two DMTs, myself and JK, who just had a few things to get signed off for his DM. AOW as taught by LSD includes PPB, navigation, drysuit, deep and wreck, the latter two done at Vobster where it goes down to below the OW limit of 18m, 5 dives in total, of which I did 4. The surface of Wraysbury had warmed up as far as 9°C, but below the thermocline at Vobster it was still 4-5°C.  My repaired drysuit wrist seal held and apart from a bit of dampness from perspiration, I was nice and warm and dry.

Altho’ we started early on Saturday, it took us a while to get into the water due to logistical difficulties: with several other courses running, and the students needing to borrow almost all their equipment, it took a lot of time for people to try things on and get comfortable, at least as comfortable as you can in a borrowed drysuit, which is very unlikely to be a perfect  fit. We were really pushed for time, exiting the water last at Wraysbury. I am not sure what we could have done differently to make that quicker. That is one thing that is very different about the UK from where I did my training up to Rescue Diver in Egypt – in a hot climate, there is no issue with popping in and out of the water, whereas in cold conditions, we need to shuffle things around to minimize the transitions, even when doing pool work.

Sunday was an even earlier start but proceeded smoothly, we met at 5:30am at LSD, loaded up the van with the previous day’s kit and set off, arriving at Vobster just before the gates opened, and parking in a reserved spot very close to the water. I did surface support for the first dive and went in for the second, the wreck dive on the aircraft, buddied with one of the students, who had hoovered through 160 bar in an instant on the first dive. I watched her and her gauges like a hawk, but there were no issues this time, due no doubt to my reassuring presence! I used 114 bar from a 12L tank in 34 mins at an average depth of 8.8m giving a SAC of 21L/min, which was slightly better than last time. I still need to do more work to improve it, especially with the maneuvering and task loading of monitoring student divers. One student did not complete this time; she was unhappy on the – to be fair – very cold and dark deep dive, and sat out the wreck dive. It’s good that we are training students with the self-confidence to call a dive, even having spent the money, traveled a long way, and potentially peer pressure to do it (not that there was any of that this time, that I could see).

The conventional wisdom is to only change, or introduce one new piece of kit per dive, but I bent that slightly this weekend, with mixed results.

  • Switched my Scubapro split fins for Hollis F1s.  These are great fins, very powerful, very suitable for frog kick. Unfortunately size XL is slightly too small for my rock boots, and size 2XL slightly too wide. I’m going to solve this by getting slightly bulkier boots I think, as I like the fins. But even more unfortunately, with an undersuit on, in my drysuit I don’t have enough flexibility in my hips to do a proper frog kick anyway! Nor would I to reach valves for a shutdown drill. That is going to be an expensive problem to solve 😦
  • Switched my conventional 5mm gloves for Waterproof 3-finger mittens, which GL had been raving about. This was a great success. Much easier to don and doff, much warmer, actually minimal loss of dexterity. You do need to remember that you’re wearing them for some hand signals tho’.
  • Switched my 3mm hood for a 5mm from Fourth Element. Warmer and more comfortable than the Scubapro, but I can’t hear a thing while wearing it! Despite that I had no problems equalizing.
  • Semi-retired my trusty Scubapro Nova torch, which has accompanied me on many adventures, to backup status and introduced a Light Monkey on a  Goodman handle as primary, on my left hand. This was also a great success, and altho’ it wasn’t dark at all, the staff having our lights on made a huge difference in the turbid conditions, often the light would be visible when even the bright yellow tanks were not. When I move up to a BP/W setup, LM will be my first choice as a canister light. Closer the time I might badger Deep Ideas to start importing LM wings too 🙂
  • Dropped from 12kg to 11kg weight. I thought I needed 10kg to be neutral, and added a little more so I could help students with buoyancy problems if necessary (it was), but this weekend I felt a lot more negative. Perhaps it is just because I am more comfortable in my drysuit now (I have only a couple of dozen drysuits dives myself, if that) but some of it will be the different fins. Next time I will just go for 10kg or perhaps even less. The formula off the top of my head is something like 7% of bodyweight + 3kg for the tank contents, which matches at my current (far from Marathon-fit :-/) bodyweight. I should be able to fit that into my BCD integrated weights/cam band trim pockets, and do away with a weight belt altogether. That will help with drysuit buoyancy too, partly because of the weight location relative to CoG but also because it impeded air migration to and from the lower half of my body.

Hmm, 4/5 of those changes involve replacing Scubapro with something else. Certainly not my intent, there’s nothing actually wrong with any of it and I am still a fan of the brand, just that I am diverging a little from the style of diving of their head of product development…

OW Completion, 6/7 April 2013

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During the week I had hastily “repaired” my drysuit’s right wrist seal by slathering on the Aquaseal, in the process discovering, where it seeped through, that the leak wasn’t where I thought it was at all! Or rather, that the seal in general was in quite bad shape. There were lots of cuts at funny angles through the neoprene.  As I have only a dozen or so dives in this suit, I can only assume that it was actually damaged by people with long nails or sharp jewelry trying it on in the shop, and had deteriorated in use. Next time, if I don’t go custom, I’ll buy one shrink-wrapped from the Internet – and feel no guilt whatsoever about going back to that shop and trying on drysuits there first. I hope tho’ that needing to buy a new one is years in the future. My repair seemed to do the job when I tested in the bath, so I have added a tube of Aquaseal to my kit. And I got a 5mm hood too.

However all this turned out to be unnecessary as I found myself on surface support all weekend, for an OW Completion at Wraysbury, two groups of three students, my group having OWSI KT, DM GL in the water as safety diver, and myself. Keen not to repeat the lead shortage of last week, we checked out everything apart from the kitchen sink from the stores, then found ourselves assigned parking for the van as far as it is possible to get from the water at Wraysbury! The whole weekend was pretty uneventful, involving making sure all the logistics ran smoothly, which I think I have a handle on now. I would have liked to have gotten at least one dive in, but I fully understand that this is “work”, and it’s still valuable experience, and better to get it out of the way and ticked off while it’s cold, and we’re at a murky pond rather that somewhere that’s a better dive anyway! I took advantage of the situation by dropping the drysuit at Mike’s for a proper wrist seal replacement and a fly zip fitting, which Christian there assures me can be ready before my next foray into cold water, currently scheduled for the end of the month. Eventually I will want a p-valve too, I expect. Later in the pub, I got some good advice from Lead Instructor AD, on needing to actively manage my own rate of progress through the DMT programme. It was good to meet some other DMTs too.

Drysuit Spec, 30 March 2013

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This Saturday saw us at Wraysbury with a class of 4 students for the Drysuit Specialty course, Duncan OSWI, plus another 4 doing an OW Completion, with an OWSI, another DMT and a recently qualified DM. I did this course myself in 2010. Water temperature 3-4°C, easily the coldest I have dived in (previously that was 9°C at Plymouth last Easter). I was actually fine in my new PBB+ undersuit bought at LIDS, and my neoprene drysuit, apart from that my right wrist seal is leaking, and my head in a 3mm hood was very cold at first. I’ll need to get both of those sorted, urgently, as I am back again next weekend, both days! Also I test-dived the Suunto Cobra I got on eBay for less than half new price. It read my initial tank pressure as 165 bar, which seemed a bit low but was possible, and my gut feel is that it tracked my air consumption correctly (82 bar from a 12L tank used in 24 mins at an average depth of 5.8m gives 25.9L/min SAC which is reasonable considering it was cold and I was swimming constantly). I need to compare it with another gauge, and maybe get it serviced too.

Specific feedback/lessons learned:

  • When doing surface support, kit up. For the first dive, I was the surface support, checking divers in and out of the water (times, air, etc), handing in or taking back weight as people buoyancy checked, keeping an eye on divers still on land or who had returned early. Another DMT had told me not to bother getting my drysuit on, but I did find myself up to my ankles in the aformentioned cold water as the pontoon wasn’t in the greatest shape, then had numb feet for the rest of the day!
  • Double, triple check kit before leaving the dive centre. We arrived on site with what we thought was 20Kg of spare lead; when we came to dive, there was only 4Kg which got used almost immediately, despite each student supposedly having been issued 10Kg at the centre. Even the belt we threaded it on was taken. I had 12Kg from the centre for myself, which vanished before I could use it (as I was surface support for the first dive, and in on the second) In the end I just rented lead to save hassle, but I shouldn’t have had to put my own hand in my pocket for this. I even had to pay to get into Wraysbury! But the DM(T) has to be responsible for everyone else too. It’s Divemaster as in quartermaster.
  • Think about where the students will be, and position accordingly. I think this will just come as I assist on more courses and get a feel for the flow of things. It’s important to be able to see everything, to be in a position to react quickly, and yet be out of the way. This means thinking one step ahead of where the instructor has put the students and what he is doing with them.

Every diver knows how to do a buoyancy check, and every diver knows that if you are overweighted, buoyancy control is a lot harder, since the air you add to be neutral at a given depth changes volume as you ascend and descend†. The really experienced divers with us, the instructors and experienced DM all seemed to be negative enough to hold down a flailing student, yet had great buoyancy control of their own without obviously adjusting their BCDs. I think 10Kg should have been enough weight for me in that kit in freshwater, but I went in with 12Kg for that purpose, yet my own buoyancy was all over the place, or at least it felt that way. How they do that is something that I’m going to have to learn. Another thing to think about is what exactly to do if a student shoots up like a Polaris. On the one hand, we are responsible for them. On the other, in a class like this they are already certified divers and responsible for themselves. Blowing an ascent rate if you only dive once a year is one thing, doing it several times a day, every weekend is bound to take its toll, even if only from 10m, and I want to go on being a healthy diver for a long time!

† When I did the Cavern Specialty in Mexico in January, we learnt one trick cave divers use: 33% of your weight is only needed for descent and to control ascent with depleted tanks, so to ensure perfect neutrality in the confined environment, they simply have some of their weight clipped on, which they leave at the entrance to the cave and pick up on the way out. Why are so many divers overweighted then? Because it makes the descent very easy and they dive a very simple profile that is down, along a reef wall say, then up (and then blow their safety stops!).