What the hell is that noise?

Contributed by Ric Mingramm

One of the mantras often espoused by Instructors and Dive Masters is know your equipment - and when (if) you become a Rescue Diver - the same words are drilled into you, know your buddies equipment!

Having gained my Nitrox qualification i thought it clever to purchase a Nitrox computer - better still I need a good dive watch - can you get one that does Air & Nitrox ... to the web! I found the yet to be released in Australia Citizen Cyber Aqualand Nx. I scoured dive shops and couldn't find anything comparable or as shiny, so via web technology I become the owner of this magnificent shiny piece of diving apparatus.

After charging it, caressing the shiny silver case it came in I thought it appropriate to push all the buttons and see what it does. I set time zones, Nitrox mixes, alarms, 24 hours clock, just couldn't get the depths to come out in metres. So after reviewing the on-line brochure and reading the hard copy I gave up and emailed the distributor and asked how to convert metres to feet and vice versa.

Q. Can I change the unit from metric to feet (or in reverse) ? A. No, you cannot change the unit.

D'oh!!!! My first lesson in cyber shopping - although I do feel special when i can dive the 100 feet submarine and all the other nancies are only diving the 27 metre submarine (softies!). Feet sounds much tougher!

Anyway to the story ...

The Aqualand can be set to sound an alarm when maximum depth is reached plus a myriad of other warnings.

Two weeks ago I had my first woops in diving - Dive 1 100 foot submarine:
This Submarine was discovered in 1984. Brass fittings and other artefacts give divers a chance to see what it was like to be a sub-mariner. The J4 lies on her keel running north south. Her bow section, which has broken away from the main body, lies facing south, while her stern faces north. The broken bow section of the submarine contains four torpedo tubes, which can be easily seen by using a torch and positioning yourself between the bow and the main body. This is the most popular of the J Class Submarines due to its relatively shallow depth, which enables good bottom times. This site is frequently used as a training ground for those on Advanced Open Water or Wreck Diver courses that cover the penetration and overhead aspects of diving on these submarines.

On this dive I was fortunate enough to utilise my skills as a rescue diver and provide my alternate air source to a novice who was breathing vapours having been so excited at diving on the submarine.

We had 100 minutes surface interval to off gas and prepare for our next dive a nice gentle rip drift dive on the flood tide. Maximum depth 18 metres or so.

We ascended down the line and held onto the float line and were gently pushed on the usual roller-coaster ride which can be the Port Philip Heads drift. After about 10 minutes the gentle ride turned to a WRX ride with the quickest rip drift I have ever done.

30 minutes later my life was surrounded by alarm sounds - we are moved to 31.6 metres - and life as I knew it had ended I was sure. My errant buddy form the submarine came up the line to me to show me that again he was running out of air. I unwrapped his hands form the float line monkey gripped his hand, settled at 10 metres safety stop and deployed the SMB to bring us to the surface.

Holding the reel,retracting line, engaging my buddy I would straight through the 5 metre safety stop to see the surfacing looming very quickly. I dumped air but to no avail. we were surfaced.

When I reached the dive boat my computers was saying i was dead, my watch was sounding alarms and juts ambled around thinking - great what next ........................

On investigation I wasn't all that concerned about the dive computer as it was working on an air profile and I was diving Nitrox but my watch that was different I was in deep do do's. After explaining the noise to the other 10 divers as they returned I was pretty chastened and I must admit quite worried I have never been and never want to be bent.

I reported my conditions and stats to the DM for registration and noticed that the Aqualand was showing I was diving on air not Nitrox! Trick for new players KNOW YOUR EQUIPMENT - the Aquarians resets the default gas to air after 90 minutes of surface interval time! I had failed to reset the mix and therefore it thought i was diving air.

I immediately grabbed the tables and worked out that i was actually 1 minute under deco time - so probably my head wouldn't explode.

All night every ache, tingle and twinge had me at the computer rechecking DCI symptoms and 2 days later I flew interstate and remember sitting in the plane thinking I hope my head doesn't explode when we get to alitude ........................

So the moral is KNOW YOUR EQUIPMENT! ON drifts keep an eye on your depth and make sure you are partner with a buddy who has gills or at least enough air for the dive.

Be safe - until next time.