trigfunctions
Contributor
Great story RedHead. It illustrates how unprepared divers can impact, and in some cases endanger, other divers. You probably had to cut your dive in half to babysit those "advanced" divers.
AOW dive in the Spiegel Grove after 12 logged dives
- Thread starter Icarusflies
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rhyz
Contributor
As a newly certified diver myself and on my last 2 dives of my AOW, I thought I'd throw my .02$ in also. Planning my trip to Florida next month I was looking to do the SG but decided not to just because of the vast changes in enviroment there. I would love to but doubt I would be able to handle a huge current at this point in my scuba career. And to do my first deep water dive in a situation that could arise there...no. Deepest I've been so far is 71' in a ocean wreck with slight current. I was very excited at being there, but was very comfortable. My SAC was thru the roof though. That was my 5th and 6th dive..total. Done 3 more wrecks dive with current and low vis about the same depth and my night dive on a wreck. I've got 11 dives in now and by my vacation will have close to 23. But even then I'm still gonna shy away from it, just because I can dive it later on when I feel i "know" I can handle a situation in a strong current.
And I'm dreading the day I get an some of the newb buddies some people describe when I start diving without my techies friends. All I count on is myself and my knowledge to pull me thru something going wrong.
If you do end up doing the dive, take care and have a great dive! I hope the conditions allow you to.
And I'm dreading the day I get an some of the newb buddies some people describe when I start diving without my techies friends. All I count on is myself and my knowledge to pull me thru something going wrong.
If you do end up doing the dive, take care and have a great dive! I hope the conditions allow you to.
lamont
Contributor
I'd also strongly recommend HP130 steel tanks (or overfilled LP104s) instead of Al80s for this kind of diving. Al80s go pretty quickly at 90-100 fsw, and they go faster when your SAC spikes due to fighting current and in general they leave you with little margin for error. At these depths, you can make mistakes and wind up with deco obligation. If you wind up with deco on an Al80 due to current, narcosis or other issues you'll probably run OOA before you complete it. And HP130 should allow you to complete a dive at these depths, with an elevated SAC rate and with a small deco obligation. You'll also have enough gas to deal with a buddy with an OOA/free-flow at depth and deal with current and higher SACs.
For reserve gas, please look up the concept of "rockbottom" on this board. At the very least a simple rule of thumb is to reserve 300 psi + 10 psi/ft for an Al80 and 10 psi / ft for an HP130/HP120 (these simple rules are approximations and fail and are not sufficiently conservative below 100 fsw). And when you hit that amount of gas you must be leaving depth and ascending. In order to get back to the upline you should split your remaining available gas into halves or thirds and when you hit that turn pressure you should start looking for the upline.
E.g.:
E8-130, 3500 psi at 100 fsw: reserve 1000 psi. 3500 psi - 1000 psi = 2500 psi usable. half usable is 1200 psi and 3500 psi - 1200 psi is 2300 psi. so when you hit 2300 psi you should start looking for the upline. if you find the upline before you hit 1000 psi you can hang out there, but must start your ascent at 1000 psi.
Al80, 3000 psi at 100 fsw: reserve 1300 psi. 3000 psi - 1300 psi = 1700 psi usable. half usable is 800 psi and 3000 psi - 800 psi is 2200 psi. so when you hit 2200 psi you should start looking for the upline. start the ascent up the upline with at least 1300 psi left.
Also, with a 0.75 SAC rate you will be using 800 psi / 10 mins on an E8-130 and 1200 psi / 10 mins on an Al80. That means on an Al80 you need to turn the dive and look for the upline after only about 6 mins and start ascending 12 mins into the dive. Not a lot of time. On an HP-130 you should hit your turn pressure after 15 mins (1200 psi / 800 psi * 10 mins) and should be ascending after 30 mins which should be about your NDL limit on nitrox.
If the current is bad, it would be more appropriate to dive it using thirds instead of halves, and you simply don't have the skill level at 12 dives to be thinking about those kinds of dives. With bad current, or bad surface conditions you should thumb the dive on the boat.
For reserve gas, please look up the concept of "rockbottom" on this board. At the very least a simple rule of thumb is to reserve 300 psi + 10 psi/ft for an Al80 and 10 psi / ft for an HP130/HP120 (these simple rules are approximations and fail and are not sufficiently conservative below 100 fsw). And when you hit that amount of gas you must be leaving depth and ascending. In order to get back to the upline you should split your remaining available gas into halves or thirds and when you hit that turn pressure you should start looking for the upline.
E.g.:
E8-130, 3500 psi at 100 fsw: reserve 1000 psi. 3500 psi - 1000 psi = 2500 psi usable. half usable is 1200 psi and 3500 psi - 1200 psi is 2300 psi. so when you hit 2300 psi you should start looking for the upline. if you find the upline before you hit 1000 psi you can hang out there, but must start your ascent at 1000 psi.
Al80, 3000 psi at 100 fsw: reserve 1300 psi. 3000 psi - 1300 psi = 1700 psi usable. half usable is 800 psi and 3000 psi - 800 psi is 2200 psi. so when you hit 2200 psi you should start looking for the upline. start the ascent up the upline with at least 1300 psi left.
Also, with a 0.75 SAC rate you will be using 800 psi / 10 mins on an E8-130 and 1200 psi / 10 mins on an Al80. That means on an Al80 you need to turn the dive and look for the upline after only about 6 mins and start ascending 12 mins into the dive. Not a lot of time. On an HP-130 you should hit your turn pressure after 15 mins (1200 psi / 800 psi * 10 mins) and should be ascending after 30 mins which should be about your NDL limit on nitrox.
If the current is bad, it would be more appropriate to dive it using thirds instead of halves, and you simply don't have the skill level at 12 dives to be thinking about those kinds of dives. With bad current, or bad surface conditions you should thumb the dive on the boat.
loosebits:
Two things should be pointed out:
1) You left the part out about aborting the dive if it dd not feel right to the diver because it did not fit your spin on things.
2) Your words head people down a slippery sloap,. If a diver should not trust or put weight in the words of the instructors when they tell'm they are ready, then why should they listen when the same people tell'm they are not?
Once again, dive safe have fun, plan your dive as well as your exit in case of trouble.
Don't be shy about backing out, if you feel it is the right thing, then it is.
kidsdream
Contributor
I posted this as another response to the same question on another board. I have mostly likely 40+ dives on the "deep" Keys wrecks including the SG, Duane, Bibb, Eagle and Thunderbolt alone, incuding 8 night dives on the Duane (that dive rocks if you have the correct experience).
I only state the above for reference because as most people said if the current is up this in not a dive for the unprepared no matter who you are with.
Last May a group of D2D'ers did a late afternoon (as it was Spring time available light was not an issue) dive on the Grove -- in addition to our group of 5 divers, there was another couple on the boat.
He was some type of caver type with marginal open water exposure (read this as: he and his lady friend were not boat savy - they where "super puckers", but I digress), she did seemed to be reasonble trained and experienced.
The current was going pretty good at the surface, meaning even though the seas were quite moderate and we did a stern tie, you had to reach for the stern line as you giant strided into the water so as not to be blown off the mooring from the beginning.
Once you were down on the wreck things were quite good - and as we were the only boat on the site (note this was about 5:30PM or so on a Saturday), we drifted the wreck from stern to bow with the the boat tieing (sp?) back up on the bow.
Now on the way back up, things really started moving and we were all waving like flags (with camera stobes arms splayed out and some reg. freeflowing mixed in to increase the fun). After our safety stops (50' and 15') this lady was quite unnerved and nearly jumped back onto the boat with a bit a fear in her eyes. I have to admit that I was huffing getting back to the boat - current/seas made a stern tie impractical.
The moral to this much to long story is that if the current is running on these type of deep ocean wrecks - less experienced divers might want to stay on the boat.
I only state the above for reference because as most people said if the current is up this in not a dive for the unprepared no matter who you are with.
Last May a group of D2D'ers did a late afternoon (as it was Spring time available light was not an issue) dive on the Grove -- in addition to our group of 5 divers, there was another couple on the boat.
He was some type of caver type with marginal open water exposure (read this as: he and his lady friend were not boat savy - they where "super puckers", but I digress), she did seemed to be reasonble trained and experienced.
The current was going pretty good at the surface, meaning even though the seas were quite moderate and we did a stern tie, you had to reach for the stern line as you giant strided into the water so as not to be blown off the mooring from the beginning.
Once you were down on the wreck things were quite good - and as we were the only boat on the site (note this was about 5:30PM or so on a Saturday), we drifted the wreck from stern to bow with the the boat tieing (sp?) back up on the bow.
Now on the way back up, things really started moving and we were all waving like flags (with camera stobes arms splayed out and some reg. freeflowing mixed in to increase the fun). After our safety stops (50' and 15') this lady was quite unnerved and nearly jumped back onto the boat with a bit a fear in her eyes. I have to admit that I was huffing getting back to the boat - current/seas made a stern tie impractical.
The moral to this much to long story is that if the current is running on these type of deep ocean wrecks - less experienced divers might want to stay on the boat.
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FIXXERVI6:
Exactly. I was looking at getting another computer and using my old one as a back up. I was looking at some computers that do trimix, in case my diving goes that far.
Then I learned that the trimix guys go down with written dive plans and a bunch of contingency plans. Now I am not sure I need a He computer because I am going to need to do much tighter dive planning and gas management if I am going to do trimix deco diving! I also need to be a MUCH better diver.
I have around 75 dives and am now realizing how dang serious it can be when I go to 90 feet in the quarry. All it took was losing a fin on a dive where I was doing some new things (6th drysuit dive, COLD water, DARK water, new regulators, etc...). I was in some danger over losing a dang fin. I sorted it out without too much trouble, but it sure made me think of how bad it could have been.
But maybe it is because I am currently doing my rescue diver book work that I worry about this guy doing the SG.
OP
Icarusflies
Contributor
Hello All;
Well, I am back from the infamous SG dive. The current was very strong, we were all waving like flags but we made it to the deck of the SG...well all but one lady in the AOW class that had to go back. Of course the instructor went with her while we waited on the deck. By the time he came back we did not have much air left so after 10 min we started the ascend with 1000 psi. The current was so strong that we did not do a second dive, we had to move to another wreck. I loved the experience of the SG with current and all but definitely not a dive to take lightly in those conditions. I ll definitely go back in 20 or so more dive and this time without instructor....of course I ll let you know to get your feed back...
PS: I am AOW now
Well, I am back from the infamous SG dive. The current was very strong, we were all waving like flags but we made it to the deck of the SG...well all but one lady in the AOW class that had to go back. Of course the instructor went with her while we waited on the deck. By the time he came back we did not have much air left so after 10 min we started the ascend with 1000 psi. The current was so strong that we did not do a second dive, we had to move to another wreck. I loved the experience of the SG with current and all but definitely not a dive to take lightly in those conditions. I ll definitely go back in 20 or so more dive and this time without instructor....of course I ll let you know to get your feed back...
PS: I am AOW now
Safe, Fun dive, Cogratulations on your AOW!
I'll be on the Eagle 9am, sounds like the current is running.
I did Davis ledge today @ 90 feet current was mellow.
I'll be on the Eagle 9am, sounds like the current is running.
I did Davis ledge today @ 90 feet current was mellow.
Icarusflies:
I wonder what would have happened if one of you had a problem while waiting on the deck for your instructor to return?
Diveral
Contributor
Glad it worked out for you. I believe the SG is beyond the abilities of most divers with your number of dives. I didn't like the fact your instructor left you (although he had a good reason). Was there a DM or safety diver along to keep an eye on you while the instructor was gone?
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