Monday, November 3, 2003

TDI Advanced Wreck Diver

InstructorJohn Bennett
AssistantMark Cox
BuddySteve Bates
Dive centerMasterDive (used as a base only), Subic Bay, Mindoro, Philippines
John Bennett and Mark Cox run the Tech Dive Academy in Port Douglas, Australia
Duration5 days
Dives1 confined water session
8 wreck dives on air or nitrox
Price750 USD
CommentsMore than just an introduction to overhead environment diving. The skills are very much the same as for cave diving, but the environment and its hazards pose different challenges.

Again, buoyancy control is crucial to perform the line laying, following and retrieval skills, through narrow to tight horizontal, vertical or inclined restrictions. Propulsion technique is very important to avoid silting up. And of course one has to be very aware of one's air reserves.

Contrary to cave diving, we were never totally gone from daylight sources, except for a short shaft penetration. Gear configuration is very much an issue here, as anything dangling or sticking out could be a potential entanglement hazard. And believe me, things do get tight in there, I've never felt so big before.

Though the skills must be mastered, they're relatively easy to learn. The main challenge really is mental. To remain in control when things don't quite go as expected.

With six divers (one instructor, one assistant and four students) we got to practice no viz exits a lot. With that many divers working their way through narrow corridors, silting up is almost inevitable. Bubbles cause falldown, holding on to a coral encrusted corroded beam causes clouds of rust particles to swirl around, just looking at something intensively might cause it to crumble.

In these no viz situations, the guideline truly becomes a lifeline. My hands must have a hundred small cuts from feeling my way around and my fingertips are pretty much worn off. The equipment seriously gets roughed up too from all the bumping and scraping. My corrugated inflator hose didn't last very long before being punctured. My wetsuit still bears rust colored marks on the thighs, from when I clammed myself in doorways. And my fins have several new scars.

The visibility outside the wrecks varied from around 3-5m to an amazing 8m the last day. A pitty really because one can not get a sense of the size of these great wrecks. Nor that some of them are actually battleships. Visibility inside the wrecks was usually better than outside - that is, untill we messed up everything.

John Bennett, current world record holder of deep scuba diving on mixed gas (308m!), is a sympathetic man, who knows what he's doing. He's a good instructor, but being four students was a bit too much to my taste. We did get a lot of training dives, but not as much actual line laying/retrieval practice as necessary in my opinion. Especially if you've never done this before. The course itself wasn't somehow as structured as the cave course I did in Mexico. There wasn't e.g. as clear a progression in skill difficulty or general understanding. There's no exam by the way.

We only used MasterDive as a base, it being located conveniently close to the wrecks. Having our own equpment all they provided was doubles with air or nitrox. The doubles were in a rather sorry condition and they didn't have enough of them. They've got no gear storage space to speak of nor adequate rinsing facilities. But what can you expect from a dive center squeezed in a cargo container.

I can't honestly recommend them. They're not very well organised and the way the local shop assistants mistreated our precious life-support equipment was beyond stupid carelessness. I've actually never seen anything like it. I couldn't have subjected myself nor my gear to their care a day longer then required. My doubles were bubbling from the right tank valve in a rather noisy way (loosing 40bar overnight), but all one of the guys in charge could say was: "He'll survive". A pity really for I would have liked to do some non-training wreck dives after the course.
Training wrecksEl Capitan: Large freighter about 80m long lying on its port side between 6 and 21m. A nice wreck where we did our initial line laying, following and retrieval skills.
 USS New York: WWI battle cruiser about 100m long, sunk in 1941, lying between 18 and 21m. Ideal for wreck penetration training. Some passages have barely recognisable permanent line.
 LST: Land Support Transport vessel lying upright in 36m deep water. Allowing multi-cabin penetration, after getting through a short but narrow stairwell. We used a deco stage here, left outside the wreck during the actual penetration.

No comments: