TDI Advanced Wreck Diver course - reflections

[ianr33]

What were you using for backgas?

 

[Peter Guy]

he left a very clear impression that cave diving was more dangerous

Funny you should mention this because we had a discussion about this during our last Cave diving trip and concluded that WRECK diving was much more dangerous than Cave diving. Those darn wrecks have stuff all over them and sharp edges to boot -- while Caves just have nice, simple passages and everything has a smooth edge. (cough, cough)

 

[DevonDiver]

Wreck vs Cave would be a silly arguement.

It all depends on the specific wreck or cave.

What would be GREAT would be a universal classification system....like the one used in climbing or mountaineering.

ie....

Class 1 (wreck or cave) - wide passages, no obstructions, no constrictions, no entanglement hazards, no silt.

Class 2 (wreck or cave) - Passages wide for 1 person easy access, minor obstructions, no constrictions, minimal entanglement hazard. Some silt.

etc etc

The categories for classification could include:

1. Size of passage.
2. Obstructions (stalactites, pipes etc)
3. Depth
4. Silt / Viz
5. Entanglements (nets, lines, wires, weed)
6. Current
7. Constrictions
8. Complexity of Navigation

 

[jamiemac]

Funny you should mention this because we had a discussion about this during our last Cave diving trip and concluded that WRECK diving was much more dangerous than Cave diving. Those darn wrecks have stuff all over them and sharp edges to boot -- while Caves just have nice, simple passages and everything has a smooth edge. (cough, cough)

I've had this conversation often with cave divers, they think we're mad deep wreck diving but you wouldn't catch me even thinking about some of the things they get up to underground.

 

[Rhone Man]

What were you using for backgas?

Just plain old air.

 

[Rhone Man]

Funny you should mention this because we had a discussion about this during our last Cave diving trip and concluded that WRECK diving was much more dangerous than Cave diving. Those darn wrecks have stuff all over them and sharp edges to boot -- while Caves just have nice, simple passages and everything has a smooth edge. (cough, cough)

Not wanting to start a fight, but a few of the comments he made were:

- in a wreck, if it all goes wrong you usually have multiple possible exit points - in a cave there is usually just one.
- in a wreck, even a really big wreck, you are rarely more than a couple of hundred feet from the exit, whereas for a cave it can be over a thousand feet
- a siltout in a wreck usually involves bigger particles, and so will clear faster, but in a cave it tends to be finer silt and so it can take weeks to settle. In addition, in a wreck, if you can work your way through a hatch you can find yourself in clearer waters again.
- because you don't utilise tie offs in caves, line traps are a greater risk

I have no point of reference, but it all seemed to make sense to me.

On the flip side, I don't suppose you need to worry about trawler nets and spider wire in caves.

 

[Kevrumbo]

Joel Silverstein, of Deep Descent fame mentioned from his actual experience in a wreck, you can always look for the glow of ambient sunlight (when you cover your primary light) coming from a porthole or stairwell etc. as a potential exit point. In fact, he commonly uses this technique/practice as a routine diagnostic on the initial line penetration of the wreck. . .

 

[BabyDuck]

thanks so much for the write up!