Wreck Diving

[h90]

The point I was trying to make is 1200 is no where near enough gas in an AL80 to complete your deep stop and safety stops if your buddy had an out of gas incident at the end of your dive. To be honest I don't think I'd even do a dive that deep with an AL80 since I've seen the light (been educated). Research turn pressures and I guarantee they will suprise you, I know I was pretty shocked. I'm diving the grove in a month and I'll be renting an HP100 to do it. Without doing the math I believe the turn pressure in an AL80 at 90' is around 2500psi. 2500psi for you and your buddy to breath off your tank and complete your stops and still have a small reserve. Someone correct me if I'm wrong here.

I may missed something, but 90 feet=27.4 meter and even with air you neither need a deep stop nor a safety stop, specially not after 15 min. Safety stop can't be wrong, but not necessary. I looked in Deco2000 and the PADI RDP.
And with Nitrox it get even less necessary.
Or did I miss some information?

 

[DiverRider]

I am a little confused by this. How was it that you had to adjust your dive because of the limitation in doing a deep dive on air while you were diving Nitrox? Nitrox has a shallower MOD than air does (especially the higher mixes) so perhaps you can explain this. And, with limited number of dives, I somehow doubt advanced gas training has occured beyond the basic Nitrox course (this is all I have so this is neither a shot nor criticism )

Ok I'm with you on the the first dive parameters, I didn't have to change my time for him. Correct me if I'm wrong here but the subsequent dive I would have had to reduce my time for him. He fell into a higher Group Designation than I did upon surfacing. His Nitrogen retention would have been higher than mine thus reducing dive time for the second dive. Sorry I excluded the fact we made two dives on the same wreck.

 

[pmlee]

The point I was trying to make is 1200 is no where near enough gas in an AL80 to complete your deep stop and safety stops if your buddy had an out of gas incident at the end of your dive. To be honest I don't think I'd even do a dive that deep with an AL80 since I've seen the light (been educated). Research turn pressures and I guarantee they will suprise you, I know I was pretty shocked. I'm diving the grove in a month and I'll be renting an HP100 to do it. Without doing the math I believe the turn pressure in an AL80 at 90' is around 2500psi. 2500psi for you and your buddy to breath off your tank and complete your stops and still have a small reserve. Someone correct me if I'm wrong here.

Maybe I am missing something, I don't see a turn pressure mentioned, just a pressure to start ascent-which to me means you should be at the line with 1200 ready to start the ascent.

I lot of people carry their knives on their bodies and not necessarily on/in a BC, attached to a hose, or in a pocket on their wetsuit. The knife/implement might not be visible post dive as people tend to put things away.

Glad that everything came out on the postive side. The Duane can be a challenging dive when the current is rippin.

 

[ScubaSteve]

Ok I'm with you on the the first dive parameters, I didn't have to change my time for him. Correct me if I'm wrong here but the subsequent dive I would have had to reduce my time for him. He fell into a higher Group Designation than I did upon surfacing. His Nitrogen retention would have been higher than mine thus reducing dive time for the second dive. Sorry I excluded the fact we made two dives on the same wreck.

I apologize if I am forgetting part of the original post because it has been a while.

Yes his residual nitrogen loading would have been higher than your because of the increased oxygen/reduced nitrogen content in your Nitrox air mixture. However, If there was only 2 dives done, I do not think you would have had to significantly alter your personal dive plan because of them. Yes, I am sure he would have hit his NDL quicker but it would have been minutes. On dive 2 of a repetitive dive series EAN32 or 36 would not gain you a ton of extra bottom time. Nitrox becomes more beneficial to bottom time with more dives. I would personally be more bothered by other points before this bothered me.

 

[Water Bug]

On subject of knife redundancy - I read some time ago that shears are prone to failure due to mechanism corrosion so I opt for a knife. Until now didn't consider the different usage for wire leaders etc. Anyone every hear of shears having problems?
Also while in Keys I saw mono at all depths - you never know and speaks to the "what if" discussed in this post.
Dive master told us a story while diving the Duane that he got his hand caught on a large fish hook while decending down the buoy line. He had to saw throught the rope in high current to free himself. Wonder what cutting tool would work best in this "what if" scenario? Would hate to be in this situation! A good buddy such as yourself would be needed.

 

[Gilldiver]

Dive master told us a story while diving the Duane that he got his hand caught on a large fish hook while decending down the buoy line. He had to saw throught the rope in high current to free himself. Wonder what cutting tool would work best in this "what if" scenario? Would hate to be in this situation! A good buddy such as yourself would be needed.

Never, ever slide your hand down an existing mooring, it is inviting a hooking event, and I am talking about a fake Rent-A-blond in Vagas.

Always place your hand on the line and look at where you are placing it.

I will only slide down an anchor line from the boat I just helped moor and know is clean.

As for being hooked, worse case is that you have to cut the line as this guy did or cut the hook out of the line or your hand.

Shears or nippers make things a lot easier.

The worst line I remember seeing was on a wreck in Cape Cod Bay. There were so many hooks it was almost imposible to even place your hand without hitting a hook.

On the two dives I did on that line I spent my deco stops cutting them out and even 20 minutes of cleaning up did not get a large percent of them.

 

[DiverRider]

Maybe I am missing something, I don't see a turn pressure mentioned, just a pressure to start ascent-which to me means you should be at the line with 1200 ready to start the ascent.

I lot of people carry their knives on their bodies and not necessarily on/in a BC, attached to a hose, or in a pocket on their wetsuit. The knife/implement might not be visible post dive as people tend to put things away.

Glad that everything came out on the postive side. The Duane can be a challenging dive when the current is rippin.

The Duane was an awesome dive that day! To top it off there was virtually no current running as I had been warned. We could manuver freely and explore things with no stress of managing current issues.

 

[divertitch]

Best to have two knives. Big one for killing attacking sharks which you can also use for stabbing fish, busting rocks, removing bits of wreck etc etc but never ever for cutting unless your snagged on some thing. The second small and very sharp knife mounted near your upper body (so you can get it with your arms tangled in fishing line) and just keep it for saving your life!! Shears are good too.