Leeds is a long way to go but it was worthwhile as Richard took me on a tour of the factory and we talked about the various options on the suit. Richard measured me up as I wanted my suit cut specifically to allow more room for shoulder movement and allow for shutdowns (the standard suit is cut very well so there really wasn’t much modification needed).

5 weeks later and my suit turned up together with the 250grm undersuit.

The following options are on the suit

- Neoprene socks
- Bellows pockets
- P valve
- Overzip
- Warm neck collar
- Repositioned dump valve

i’ve been testing it for the last month of so and I’m very pleased with the build quality and the fit. Its cut for a 250grm undersuit (though having dived it with a 400grm santi its still usable) and there is plenty of room for shutdowns and general movement.

The telescopic torso is a different design but works well and enables a high degree of flexibility. The warm neck collar is a cut down redesign and far less intrusive than the original. Pockets are well placed and certainly big enough for all the stuff I normally carry.

I’ve elected not to fit drygloves to this suit as the fourth elements that I have work so well but I do know several people that have successfully fitted rolocks and been very pleased with the results.

The undersuit is very warm and for runtimes of under 2 hours when combined with a base layer sufficient to keep me comfortable.

The material of the suit is very hardwearing and yet still flexible - it will take longer to dry than something like a TLS but the ability to turn it inside out thanks to the softsocks means that the interior of the suit can be dried very quickly. In all honesty its the driest drysuit I have ever used with minimal leakage.

Softsocks work extremely well - you obviously have to be careful where you stand but when combined with allstars or wetboots then they are great for flexibility and being able to perform different kicks.

So I’m pleased with the suit- its works well and the backup and support from Seaskin is superb. Its going to get very well tested in Scapa but I’m sure that it will be upto the job.

I recently changed the name of the Website to IanDennisTechnical as I think that it gives a better representation of the type of training that I offer to divers. The response so far has been extremely positive with more students finding me on the web and more courses running.

The plans for 2009 include

• Running Normoxic Trimix courses from Feb 2009
• Incorporating a DESAT training programme into the course structure
• Becoming a BSAC advanced instructor
• Trips to Scapa Flow, Malta and Norway
• On line calendar for training course availability

So lots of things in the pipeline and lots more courses running so if you would like more details then please do email or call me on 07701033022

Designed in 5mm stretch neoprene, they were certainly warm - the seams have been sealed to minimise water penetration and they are were very easy to put on as there is just the glove and no fancy velcro.
Normally I struggle with 5mm gloves, sometimes getting hand cramp and prefer to use drygloves but these were a revelation- the fit was really good, dexterity was excellent- doing demos of shutdowns I had plenty of feedback from the gloves. Whilst the water was warm enough to go without gloves I wanted to try these out as I’m doing some deeper stuff at the weekend.

Two dives - about 90minutes each one, and the gloves performed superbly. The coated seams really do cut back on water penetration and my hands were very warm during the dives. The feel is great and the texture of the gloves provided a good grip.

So I will be using these on a couple of 60m dives at the weekend and plan on using these to see what they are like compared to the rolocks. I’ll post a follow up

My initial thoughts are that these are really good gloves that offer superior levels of feedback compared to normal 5mm gloves and that they are really comfortable. For those of us that are looking at alternatives to dry gloves then it might be worth getting a pair of these instead.

The course was originally intented as a workshop for both the Advanced Nitrox and Advanced Recreational Trimix courses to provide students coming on these courses with a grounding in such things as propulsion, Out of Gas drills and Valve Shutdowns.  Many previous students had struggled with the concept of the valve shutdowns and this course was designed to give a training ground so that time on courses was not spent developing basic skills.

Any course strives to train students in new skills but the valve shutdown is recognised as causing the most problems and its an area where an additional day spent training can produce real benefits. For courses such as deep diver where students have never dived using a twinset before then it is an essential component of further training.

Twinset fundamentals takes the basic skills a single cylinder diver may already have and incoporates the use of twinsets into that skillset. Whislt most divers have a grasp of buoyancy control, the fundamentals course seeks to further improve the level of buoyancy control before then developing additional new skills such as Long hose donation, shudowns, mid-water mask removal and replacement and other practical skills.

The day consists of a briefing lecture about the history and mechanics of twinsets and their components followed by a session on equipment configuration, the various types of wing and harness available, sizes of twinset etc.  We then have a dry land skill session involving the procedures for gas donation and valves shutdowns.

For the practical session 2 training dives are carried out with a minimum in water time of 120minutes- these dives incorporate various skills and techniques - more details can be found at

http://ianDennisTechnical.co.uk/training/twinset-diver/

IANTD are at the forefront of diver training and we are constantly seeking to develop new training programmes to benefit divers. One of the new developments is the launch of the Advanced Recreational Trimix - TRIOX course designed for divers wishing to dive in the 30-45m range and take full advantage of the benefits of decompression diving with Trimix.

Where previously divers have been limited to using weak Nitrox mixtures with the associated levels of inert gas narcosis, or undertaking full trimix training with its associated cost, there is now an alternative training route available.

The TRIOX course offers the ability to learn all the procedures covered in an Advanced Nitrox but with the added benefit of the availability of Trimix for deeper dives. Incorporating decompression training the course enables students who qualify, to dive to 45m and carry out the required decompression stops.

For UK diving this represents an idea course with divers gaining the ability to use trimix mixtures in the recreational range, and incorporating all those skills previously associated with Advanced Nitrox such as Out of Gas drills, Valve shutdowns, stage handling, team development, situational awareness and precision buoyancy control.

As recently reported in Diver magazine Triox represents the next step forward, so take advantage of this course today and take your diving to the next level.

More information about the course can be found here Advanced Recreational Trimix

One of the princpal questions in any diver’s mind when considering taking up technical diving is the choice of the right equipment. There are a vast variety of different configurations that can be seen at dive sites up and down the country, each may have its respective merits and divers should be able to make an educated choice about which type best suits their diving. Any instructor should have sufficient knowledge to advise students in an unbias manner and highlight both the positives and negatives of any configuration. Kit choice can be an emotive subject and on internet forums it is debated as a regular topic, with subjects ranging from the whether cylinders should be the inverted or mounted traditionally to whether a single piece harness is appropriate for diving from inflatables.

For IANTD Advanced Nitrox and Triox courses we teach Hogarthian style - the equipment requirements are quite straightforward and listed below:

Twin set with isolation manifold in test and in oxygen service - Minimum, twin 10’s ltrs

Side slung decompression stage cylinder in test and in oxygen service - Minimum 7ltrs

2 x regulators for twin set:-

1 with a 2m hose and LPI and 1 with a short 2^nd stage hose and SPG.

1 x regulator for decompression stage with sort 2^nd stage hose and short SPG hose or button gauge, may also be fitted with LPI for drysuit inflation if a seperate system is not being used.

Harness and wing.

Dry suit, hood, and gloves and appropriate thermal insulation

Fins and mask.

Slate and pencil.

Primary Torch- an umbilical torch would be preferrable but is not an essential.

Backup torch.

Reel and delayed Surface marker buoy.

2 x depth timers - (Or equivalent means of monitoring depth and time including dive computers that can work in Gauge mode)

If you have any questions in connection with these requirements then please contact me to discuss.

Method 1

Diver conducting the drill ensures that team is aware of his/her intention to conduct a valve drill

Check Back up reg with brief purge

Close Isolation valve fully whilst signalling team that you are closing a valve

Swap from primary regulator to back up

Close right pillar valve whilst signalling team that you are closing a valve

Re-open right pillar valve, ensure 2nd stage working by purge, swap back to primary

Swap light from left had to right

Close left pillar valve whilst signalling team that you are closing a valve

Re-open left pillar valve

Return light to left hand

Re-open isolation valve

Complete flow check on all valves to ensure open

Signal drill completed

Method 2

Diver conducting the drill ensures that team is aware of his/her intention to conduct a valve drill

Purge backup regulator to verify operation

Shut down the right pillar valve whilst signalling your team that you are closing a valve

Breathe down the primary regulator and swap to backup

Clip the primary regulator to right chest d-ring

Re-open the primary, unclip the 2nd stage and purge to verify operation

Switch from backup to primary

Close the isolator whilst signalling your team that you are closing a valve

Re-open the isolator

Swap light from left had to grasp in right

Close left pillar valve whilst signalling your team that you are closing a valve

Purge back up regulator

Reopen left pillar valve

Briefly purge backup reg to ensure working

Return light to left hand

Conduct a flow check to ensure all valves open

Signal drill completed

Both of these accomplish a complete shutdown of the entire system and with practice they can be completed quickly and with minimal movement in the water column. One of the key things to ensure is that the trim position of the diver in the water is correct. With good trim and positioning then valve drills become significantly easier.

Uwatec recently replaced their long serving bottom timer with the new 330m model. It has some improvements on the old model with a clearer screen, an ascent rate in metres and a dive timer that runs to 99hours amd 59minutes. The previous model could not exceed 99minutes or dive beyond 99m.

I really like the simplicity of the bottom timer- it just gives the information you need on a clear display. The screen is clear, but easy to scratch and best protected by some clear film, such as that used to protect pda screens. The depth, time (no seconds) and max depth are all very clear and the lower right display cycles through average depth and temperature. The average depth is the mean taken from the surface and reads shallow when compared with an Aladin tec G2 reset at the bottom of the shot. Its not a huge problem but divers using average depth for their decompression planning need to appreciate that the reading will not be the true average depth. The ascent rate in metres per minute is quite useful and easy to read. Not having a backlight causes little problem as the screen is easy to read in torchlight, due to the high contrast of the digits.

When combined with a niknaks mounting and two bungee loops the bottom timer is secure and reliably stays in place. I have experienced no problems with this model and really do appreciate its clarity. It would be nice to have an average depth feature that you could reset but this would require a complete redesign of this trustworth unit.

If your looking at following a run time schedule as a primary method of diving then this timer would make an excellent addition to your diving equipment. It also makes an excellent back up in the event of primary computer failure.

www.scubapro.co.uk

Diving throughout the year one of the common problems that I see is divers who are ubale to compete some skills due to a loss of dexterity as a result of cold water. Some divers choose to dive in 3mm gloves, some in 5mm, some in semi drygloves and some in drygloves. The extremities are the first area of the body to feel the effects of cooling and by preventing this cooling, you can increase the retained core temperature and warmth on a dive.

Like others I have tried the wrist seal drygloves and whilst the first goes on without too many issues, the second is very difficult to fit. Scubapro used to make a 5mm semi-dry glove which was really good at keeping you warm but which wore through the material quite quickly. They now make this glove with a kevlar material which unfortuantely reduced the dexterity even further.

Personally I like warm hands and so I invested in a set of rolock drygloves to fit to my protec explorer. The rolocks come with 4 rings, 2 for the suit and 2 for the gloves. The rings lock together by lining up the dots and twisting on, friction then holds them in place for the duration of the dive. Taking the standard Showa 660 gloves they can be fitted to a drysuit very quickly. The link for fitting instructions is here

Once fitted to the suit they preserve the inner seal so that in the event of a glove flood the entire suit is not compromised. Diving without an inner seal does mean that should the glove develop a leak there is the risk of a suit flood. In order to equalise the glove, which becomes compressed as the depth increases, their either the inner glove can be put on prior to the seal or you can use a small tube to enable gas flow through to the glove. I use short WD40 straws to equalise and in diving down to 60m have never had a problem.

The rolocks once locked on, if fitted correctly, will not unlock without a full twist on the wrist. Getting them in the right place normally means lining up the dots with the middle finger. For me they need to line up with the ring finger inorder to get a reliable lock. Though once locked on they do not move and I have a considerable amount of confidence in their ability to keep me warm throughout the dive.

I have used them extensively over the last 12 months from the NADC to Scapa and wreck diving on the south coast- you do need to be a little more careful where you put your hands in order to prevent cutting through the material but I have found them to be very reliable and extremely comfortable. Replacement gloves can be obtained from protec direct if you have large hands like me. Alternatively you can use this supplier for standard sizes.

Rolocks are more expensive than some of their compeitors such as typhoon and Northern Diver but they do have some major advantages in the speed of being able to replace gloves compared with the typhoon (or chekup systems) and the size of the rings when compared with ND. Niknaks are now doing the ring sets at £99 which is excellent value.

Whats happens if they flood ?

Well you do get a wet hand!

Diving in the NDAC last year at 45m in 6 degree water one of my gloves leaked as a result of some small holes (had been wreck diving the week before). Whilst the glove was full of water by the end of the dive, my hands were no colder than using a 5mm wetglove- the thermal protection is important here - I was diving with a 40grm thinsulate inner glove which prevented too much heat loss. Merlino wool also works very well-especially as an inner liner glove underneath the thinsulate. There was a small amount of leakage to the suit arm but again chosing the right undergaments meant that I was not chilled by this- a 400grm Santi does keep you warm.

Unless you experienced a total glove failure or rip then you should be no colder than a wet glove. I am now sufficiently happy that I will use the rolocks on deco dives in cold water- they are a good system which provided you are aware of the limitations permit great thermal protection for the hands.

I also prefer the rolocks to the zipseals now found on DUI suits. Zipseals have the advantage of a flexible ring system but they have no inner seal. With the rolocks if I want to switch to a wet glove then I can without any problems, with zipseals I would need to replace the entire seal with a latex seal prior to the dive. Whilst the rolocks have bigger rings this is not really a problem and I would recommend them to any diver looking to increase their dexterity and comfort whilst diving in colder waters.

In my experience those students that want to dive safely beyond recreational depths are now electing to take either Advanced Nitrox or Advanced Recreational Trimix as their foundation course for diving to develop the necessary skills and training for this type of diving.

Trimix is a combination of three gases- oxygen, helium and nitrogen. The idea behind trimix is to displace nitrogen with helium so that the drawbacks of breathing high partial pressures of nitrogen- inert gas narcosis-can be reduced.Typically the air we breath is composed of about 20.9% oxygen, 79.1% nitrogen and .033% carbon dioxide plus various intert trace gases. This is fine until we start breathing air under water. As we go deeper the partial pressure of these gases increases and we begin to suffer side effects such as mental impairment, mild euphoria,task fixation and reduced intellectual capacity. Divers can experience these effects from depths as shallow as 25metres.

In order to combat inert gas narcosis we can utilise different gas mixtures to reduce our tissue loading of nitrogen and hence our level of narcosis. Nitrox is the gas of choice down to 30m as it extends no-decompression limits through the use of oxygen and reduced nitrogen tissue absorption. Beyond 30m nitrox has issues surrounding oxygen toxicity, for example utilising 32% nitrox the MOD at 1.4ppo2 is 34m. Most training agencies suggest that oxygen exposure should be kept to 1.4ppo2 for bottom gas in cold waters such as the UK where we may be working against the conditions.

If we are diving deeper than 30m then trimix has substantial advantages as the narcotic effects are nil. Helium is less dense and breathing resistance is significantly reduced and helium off-gases rapidly and its does not enter the slow tissues as readily as nitrogen. There are some disadvantages in that helium conducts heat 5 times faster than air and that ascents need to be carefully managed in order to comply with decompression requirements.

Deep air used to be the only solution before Trimix training become available. Nowadays there are better options for divers wishing to go beyond 30m. Inert Gas narcosis becomes an issue beyond 30m and although divers believe that they can develop a resistance to narcosis, in truth this is more fiction than fact. Regular deep air divers can get used to dealing with the reduction in mental capacity but the sad fact is that when they need to react to a potentially dangerous situation then inert gas narcosis can prevent them reacting quickly and correctly. Whilst training and basic muscle memory can help the air diver, a diver on a Trimix will always be better able to react due to the reduced level of narcosis.

Some agencies continue to offer deep air diver training without the requirement for the use of a twinset. If a diver calculates their own level of air consumption it soon becomes apparent that 3ltr ponies are insufficient to safely get a diver back to the surface should something go wrong with their air supply. Air consumption can rise to 100 litres per minute under stress, and sustained rates in excess of 35 litres per minute have been recorded. A typical pony has a total capacity of 600 litres and at 40 msw (5 bar) then the diver could be using 175 litres per minute whilst at depth. During the ascent the diver could maintain 35 litres per minute and in that event have insufficient air remaining to safely reach the surface. Using a twinset would enable the diver to enjoy a larger gas reserve if observing rule of thirds or minimum gas levels. Additional using Trimix would enable our diver to react more appropriately and seek the assistance of his team to rectify the problem.

With the availability of Trimix courses and training then today there is little need for deep air diving in the Uk. Granted in isolated areas without the benefit of Helium it may remain the only solution but in the UK divers are steadily moving toward the safer options of Trimix for beyond 30 msw.Whilst any dive beyond 30m carries a degree of risk by using the appropriate equipment and training together with the correct gas then divers are able to enjoy diving safely beyond these limits.

If you would like more information about developing you diving to take advantage of either Nitrox or Helium based mixtures then please contact me via email or the above telephone number

Rest and hydration together with a full dive plan in accordance with your current level of training can help to minimize risks but in the event that something does go wrong then the common symptons include :

Joint pain, numbness, weakness and tingling in the extremities, loss of sense of balance , skin rash, visual disturbances, nausea and undue fatigue. If a diver exhibits any of these symptons then consult with the DDRC on 01752 209999 or the London Diving Chamber on 07940 353 816.

If you suspect that a diver has DCS then it is essential to seek medical help. It is crucial that hyperbaric treatment is arranged quickly- ideally within an hour for conscious patients and less than a quarter of an hour for unconscious patients. If the patient is conscious and can swallow without difficulty then administer water to aid rehydration.

100% oxygen should be administered without any breaks (other than for fluids and such breaks should be kept to a minimum) and maintained. Avoid the patient breathing air unless there is no other choice.

Keep the casualty lying down

Give them 100% oxygen via a tight fitting mask

Give them fluids - non alcoholic and non caffeine

Keep the patient comfortable

Dial 999 or 112 on any public phone or mobile within the Uk and ask for the Ambulance Service confirming that it is DIVER emergency- be sure than you know the exact location, the divers personal details, the GAS the diver was using and the nature of the divers injuries and profile if possible.

On board a vessel then ask the skipper/cox to call on channel 16 - PAN PAN PAN Diver emergency. The coat guard will then be able to advise on air lifts and procedures. Again the more details your able to provide the better- personal details for the diver, GAS used and profile for this and nay previous dives all helps the patient receive the best possible treatment.

Hyperbaric treatment can be arranged via DAN for its membership on 0039 06 4211 8685 or in the UK on 0870 871 9999- 24hours a day, 7 days a week.

I strongly recommend that divers undertake courses involving 02 administration and basic first aid and that they have access to these telephone numbers when diving from shore or at sea.

Scubapro have recently relaunched the G250 with a rebadged V version to take over from the G250Hp. Many divers had stated that they preferred the metal barrel inside the original G250 rather than the plastic Hp version- hence the reason why Scubapro haven chosen to relaunch this model.

Having recently acquired the G250V I though that it would be a good idea to test it. Following a brief try out in the pool, I took it on an easy dive to 42m at Chepstow and it performed really well and no problems were encountered. The G250v is quite light in the mouth and is fitted with a quality mouthpiece that prevents jaw ache. After a 30min dive I felt no discomfort and would happily of carried on further with the dive. On my deco stop then swapping over from 28/25 trimix to 50% then I couldn’t really detect much difference between the G250v and the Hp, the actual design difference between the two is that slight.

I having been diving with the Hp for quite a while and use it on several of my stage bottles, so have probably grown used to it. The one advantage that the V seems to have it that one does not suffer the dryness of mouth that is sometimes found on the Hp. Whether the G250v is actually any better than the Hp is open to debate- the components and design are very similar. The revised styling looks very good and certainly it seems a substantial regulator.

So in summary the new G250V is an impressive regulator, as one would expect from Scubapro and it seems to be well built and able to supply gas comfortably over a range of depths. The controls are slick and the regulator sits nicely in the mouth with the new scubapro mouthpiece being a standard fitting.

I use mine on my twinset with the G250v on the primary long hose and an R190 as backup, some divers will argue that you should have two high performance reg’s on your backgas set up, however this can lead to problems of sensitivity and freeflows, in strong currents or when in cold water and whilst high performance balanced regs can be detuned in my view it is better to stick with a non-balanced backup such as the R190 as it has proven to be totally reliable over the years. G250Hp’s are on my stage bottles as I like to switch over to a high performance regulator when switching over to deco gas. All my first stages are MK25’s, with the exception of my pool reg that is a Mk2. I have tried other regulators but few regulators can match the design and hose routing of the MK25 for both single cylinders and twinsets.

When coupled with a MK25 then the G250V would make an excellent choice as a primary regulator for both the recreational and technical diver.

www.scubapro.co.uk

g250hp-repair-guide.pdf