Dive gear maintenance: Gauges

The depth gauge is most often prone to sand build up on the sensor. Scubapro are really bad for this because the sensor is covered by a flimsy sticker, which lasts all of about 10 dives, and the gauge will often show 3-4 metres’ depth out of the water.

Leaking high pressure hose
Leaking high pressure hose

Remove the gauge from its rubber holder and rinse the sand off around the sensor and in the molded rubber housing. Avoid pressure on the sensor as it is extremely sensitive.

Smacker monitors the testing of a leaky gauge
Smacker monitors the testing of a leaky gauge

The source of many minor leaks is often the swivel pin. These seals will be changed when your gear is serviced.

Not everyone will agree with this but I take a sponge with liquid silicone on it and wipe my hoses, regulators, and gauges. I leave it on for a minute or so and wipe it again with a clean dry cloth. I also wipe the thread of the A-clamp screw or yoke threads with the silicone sponge. I find this prevents corrosion and salt build up on the gear and I have a Mares regulator with well over 1000 dives that looks and works well.

Chamber dive revisited

Sealing the inner chamber door
Sealing the inner chamber door

We recently did a chamber dive to 50 metres. A hyperbaric chamber is a sealable chamber, or pressure vessel, somewhat like your dive cylinder (just larger), and has hatches large enough for you to climb in. It is connected to an air compressor or a bank of compressed air, and once you’re in and it is sealed the pressure is increased just as the pressure around you increases as you descend. You need to equalise as you do under water, the only real difference being is that you are dry. A fast descent means constant equalizing and ensuring deep breaths are taken. You will experience nitrogen narcosis, the extent will vary from person to person and you voice will change.

Our hyperbaric chamber
Our hyperbaric chamber

The video below shows us counting backwards from five, showing the correct number of fingers and turning our hands round after each number. It’s hard when you’re narced!

[youtube=http://www.youtube.com/watch?v=zWX-X5RngUs&w=540]

As a recreational diver you will find that your PADI eRDP will not allow you to enter a depth greater than 40 metres when you plan a dive, and the recreational dive planner (RDP or dive tables) will not allow planning deeper than 42 metres. The chamber operator or anyone that does deep technical diving will have a program to enable proper dive planning and ensuring the correct dive profile is maintained, by means of decompression stops.

Checking on the first group of chamber divers
Checking on the first group of chamber divers

On our dive we descended to 9 metres, and paused whilst two way communication was tested and the operator checked everyone was okay. Thereafter we dropped like a stone down to 50 metres in two minutes. Our bottom time was nine minutes. Nine minutes at this depth gives you quite a decompression commitment and we ascended slowly doing several deco stops on the way up with a total dive time of 39 minutes.

My Mares Nemo Wide showing the dive stats
My Mares Nemo Wide showing the dive stats
Citizen dive computer
Citizen dive computer

Our dive computers all joined us for this dive and were placed in a bucket of water (some dive computers will not go into dive mode unless the water contacts are activated). I had a Suunto Mosquito, a Mares Nemo Wide, an Uwatec Aladin Prime and a Citizen dive computer as well as a wrist mount depth gauge.

My trusty Suunto Mosquito showing the dive stats
My trusty Suunto Mosquito showing the dive stats
The Aladdin that Clare usually wears
The Aladdin that Clare usually wears

The computers were all similar in readings and were all between 50.1 metres and 50.4 metres whilst the depth gauge showed 59 metres! It’s safer for your instruments to err on the side of conservatism (i.e. tell you you’re deeper than you are, rather than the other way around). This depth gauge probably didn’t know what hit it!

Analogue depth gauge with red needle showing maximum depth
Analogue depth gauge with red needle showing maximum depth

A very important deep skill on a PADI Advanced course is to compare your depth gauge with your buddy and your instructor. There can easily be huge variations in depth gauges.

Goot checks his computer
Goot checks his computer

Newsletter: 50 metres and Gordon’s Bay

Hello all you divers

Tracy, Goot, Sophie, me, Tami, Bernita, Clare and Cecil outside the chamber
Tracy, Goot, Sophie, me, Tami, Bernita, Clare and Cecil outside the chamber

We have just come home from a 50 metre chamber dive. We were two groups of four on each dive and the profile went like this: surface to a brief stop at 9 metres to check that everyone was okay and then a plunge down to 50 metres in two minutes, ten minutes at this depth and then around 25 minutes for the ascent with a few stops to decompress.

50 metres down...
50 metres down...

We took a small sample of a wetsuit with us, this compressed to paper thin material. Two balloons, inflated before the descent, shrank to the size of a fist at 50 metres. We took several dive computers and a wrist mount depth gauge. The computers agreed more or less on the depth we reached, 50.2, 50.4 and 50.1 metres. The analogue depth gauge showed almost 60 metres. Great fun and a safe way to experience chronic nitrogen narcosis.

Clare examining the controls of the chamber
Clare examining the controls of the chamber

Last week

Evil-eye pufferfish at Long Beach
Evil-eye pufferfish at Long Beach

We had three good days of diving last week and saw a huge ray, several cuttlefish, puffer fish, and of course the regular octopus. There have also been huge schools of yellowtail, the fishermen were netting a few hundred an hour on the northern end of Long Beach. All the dives last week were interesting as a big school of tiny anchovies followed us around.

Two tiny cuttlefish at Long Beach
Two tiny cuttlefish at Long Beach

We dived at Long Beach on the weekend, Corne doing Divemaster training, Marinus and Dean doing dive three and compass work for their Open Water course, and Sarah finishing her Open Water course.

Dean practising compass work under a towel while Marinus and Corne look on
Dean practising compass work under a towel while Marinus and Corne look on

The water was 15 degrees and the visibility was low, perhaps 3-4 metres. We were able to capture a small feeding frenzy on camera below the bow of the wreck where a few species were after the same food, the winner being the shyshark who took it all in one bite. I’ll send a link to the video in the next newsletter.

Sarah impersonating a manta ray
Sarah impersonating a manta ray

Sunday’s planned boat dives were cancelled due to a red tide hitting the coastline and turning the water into coffee. Clare, Lukas and I did a photography dive to check it out and had less than 2 metres visibility.

This weekend

This weekend will be a little tricky. The Argus Cycle Tour is on and its around the peninsula so there are going to be road closures on Saturday evening and Sunday. Saturday they are closing the road late so we may be able to dive from Hout Bay but will only know on Thursday if this is going to happen.

Sunday is definitely out so we are planning to head off to Gordon’s Bay, weather permitting. The plan is for Grant to take the boat out really early, check out the conditions and then give us a call. You will need to either escape the race, participate, or stay home so why not come to Gordon’s Bay and we go wreck hunting. The diving there is lovely and conditions are good there when our side of False Bay is a mess because of the southeaster. We’re going to make a day of it and have lunch and an ice cream afterwards.

If you want to come diving on Sunday please let me know before midday on Friday because the boat will fill up very quickly with NON-cyclists!

Sodwana

Sodwana divers please send me a list of gear you will require so we can get it planned and arranged. We will have a dinner at our house for the group about 10 days before we leave to get all the final arrangements sorted out. I will let you know amounts owing in a separate mail.

Courses

I am currently running Open Water courses, Deep specialty, Rescue and Divemaster. The Deep specialty qualifies you to 40 metres so if proper exploration of those wrecks in Smitswinkel Bay is on your bucket list let me know and we can do some deep diving.

I am going to run two special programs over the next month, one being a package of Open Water, Advanced and a Specialty – e.g. Wreck, Deep or Nitrox – at a half price. Secondly do Discover Scuba Diving any weekday for R350 and if it is for a friend of yours you can tag along for free.

regards

Tony Lindeque
076 817 1099
www.learntodivetoday.co.za
www.learntodivetoday.co.za/blog

Diving is addictive!