Wreck Penetration

[Jim Lapenta]

Most recreational courses that offer "limited penetration" if taught by the book to minimum standards are more likely to get a diver in trouble on subsequent dives. There is not enough emphasis on line use, tie offs, light use, touch contact, rescue, and entanglement detection and avoidance.
When I teach the SDI Wreck course with the limited penetration option it is a minimum of 6 dives and while preparing for the TDI Advanced Wreck course I can offer, it is also about how many ways wreck diving can kill you or allow you to kill your team.
Cavern is a good start for line use and overheads but there are some serious inherent differences in going inside a cavern and going inside a wreck. A NAUI Cave Instructor Trainer once said at a presentation "that wrecks are inherently more dangerous than caves in some respects."
Many if not most caves have been there for hundreds if not thousands of years and been relatively stable. A wreck can literally change overnight. Hulls and passageways collapse, hatches that were open are now closed, hidden cables and conduits are now tentacles reaching out to ensnare, unexplored sections that look perfectly fine on the way in become silted out black areas from the exhaust bubbles hitting the ceiling.
Wreck line laying can be different also. Tie offs have to be chosen so that they can be secure but also undone without excess effort on the way out because you normally don't leave the line. They have to be selected to ensure that the line is not going to rub against a razor sharp piece of metal. They need to be chosen and marked so that some untrained person on another boat doesn't come and try to remove them OR WORSE, follow them into the wreck behind you.
Serious technical wreck diving is often going to involve some deco because the best wrecks are often deep. So before any wreck penetration training a good recreational wreck primer followed by Advanced Nitrox and Deco, perhaps a Helitrox course as well, with some time, racked up doing decompression dives is a start before a technical wreck class.
Then I advise students to practice some of the skills as often as the can in shallow water like line laying, tie offs, blackout mask use, and light use before getting into the technical wreck training.
It's not something to be rushed. And not something to do in a couple weekend classes.

 

[TMHeimer]

I took the basic PADI Wreck course years ago. We did quite a bit of line work, both out of and in the water. We did penetrate a tube-like structure which did resemble a shipwreck. One interesting thing covered was a "line trap". However agree, I would not do any penetration with just that backround.

 

[jlcnuke]

Thanks for the insight so far everyone!

 

[Blasto]

I was under the impression that skill in the water is much more important than number of dives you have. I've seen people claiming to have 2000 dives that can't get into proper trim, have rubbish communication, conduct cowboy dives, and have mediocre buoyancy.

Of course. 500 wreck dives is just a rough guideline for what I would feel as a suggested minimum between one's first penetration class (own line) and even thinking about penetration through tight restrictions, ones too tight for BM to be tenable.

Skill in the water is one thing, skill in the environment is another, and you need both. The best open water skills won't help you find your way out of the engine room when a pipe collapses, takes your line with it, and raises enough silt to make your lights useless. Thousands of wreck dives will, that I know, because I've seen a teammate do that.

(Not actual silt, more like clouds of dark brown rust. You get a layer all over the inside of your gear when you're out. They're really good at blocking out light too.)

 

[_Ralph]

Coming as a wreck, and then cave diver, heres my thoughts.

The first step will be a recreational wreck class. This may teach some line work, may incorporate some easy penetration (no corners, mainly swim throughs).

A cavern class will spend a considerable amount of time on trim, propulsion, buoyancy, line work, tie offs, placements, line protocols, team protocols, navigation,etc

An advanced wreck course will put those two things together.

Wrecks are generally deeper than cavern zones, and can take some time to navigate, so having trimix/decompression training under your belt will aide in spending quality time inside the wrecks.


Simply put, there isn't an all in one course to take. Small steps will make the end goal easier to manage, but will take longer to get there. You can apply those skills as you progress and acquire them to do more advanced diving down the road, and smaller steps allows you to master those skills easier in smaller chunks.


_R

 

[Mary Maryland]

I know this isn't about the OP, sorry.

Marie

Don't they fit lifts on your boats?

In the old day's we, used to use ladders. When I started 'technical' diving, we started dekitting in the water and winching kit out, especially on the bigger boats, converted trawlers with 6ft+ freeboard. Dekitting sounds easy, but in rough seas its as dangerous as climbing up the ladder. One of the bigger risks was being hit by the ladder. On a rolling boat I've seen the bottom of the ladder well above me, and then well below me. Once you're on, its a little like being on a roller coaster that dunks you!

Now, there are very few UK boats that don't have lifts. I have to say its significantly improved safety. It's much easier to get a casualty onto the deck with a lift than trying to parbuckle them up the side of a boat, or winch them out.

Gareth

None of my half-dozen liveaboard trips has had a lift. I’m diving Palau on the Aggressor in March 2019, and I don’t see a lift in their advertising. A lift would be a big draw imo. Mary.

 

[Akimbo]

None of my half-dozen liveaboard trips has had a lift. I’m diving Palau on the Aggressor in March 2019, and I don’t see a lift in their advertising. A lift would be a big draw imo. Mary.

The Palau and Rock Island Aggressors both have hydraulic lifts for the tender:

​

You can see it operating around the 9 minute mark in this video. I understand that the reason these boats use tenders is because they often live boat in high currents/drift dives. The deck plan shows the tender in the "up" position:

This is not a diver lift but still saves a lot of stair climbing compared to diving off the liveaboard. You always have the option to doff your tank and hand it up to crew before climbing the ladder.

 

[tursiops]

None of my half-dozen liveaboard trips has had a lift. I’m diving Palau on the Aggressor in March 2019, and I don’t see a lift in their advertising. A lift would be a big draw imo. Mary.

On both Palau Aggressors the diving is from dinghies, and the dinghy itself is lowered to the water, and raised at the end, by a hydraulic lift. You backroll into the water, but have a ladder to reenter the dinghy.