Nitrox on the spiegel grove

[7ftDiver]

trying to plan ouut my dive on the spiegel grove, any suggestions on what mix. I was thinking EAN30 or 29. This assumes i dont drop below 110' is there much im missing by sacrficing that extra 20 ft? ill be diving from a boat so ill have 2 dives to make probably with a short SI so i cant max out my O2 exposure on the 1st dive

 

[SDAnderson]

Nitrox is groovy for shallower dives but at SG depths there is limited benefit unless you are planning multiple dives on short surface intervals.

That said, EAN28 will get you to the bottom, should you decide to go there. Everybody runs their own calculations for NDL limits, but the difference between 28% and 30% at anywhere from 100 to 120 feet doesn't start to diverge until you get close to the 20 minute mark - impressive bottom times for a single tank with a moderate to heavy work load.

Don't forget - blending to within a single percent is a bit of a trick and your analyzer isn't reliable enough to reliably evaluate that kind of discrepancy, anyway.

 

[reefman]

iv'e got 10 dives on the spiegel since it turned upright, and use a 30 to 32 mix. there's need, in my opinion, to descend to the sand(approx 130ft), as the majority of the sea life is between 70 and 110ft(primarily from the stern to midships).


reefman
key largo

 

[Talon]

I do the SG on 30-32%, but of course I'm not one of those believe who believe I'm going to die the second I hit 1.4 either

 

[BigJetDriver]

NN II or NOAA Nitrox 32 or EANx 32 has an MOD of 130 fsw. I have had no problems diving it on the Spiegel, with the sand at 130.

Your exposure time is limited, with a single 80, especially since you will want to look at as much of the boat as you can. (I assume here, that you don't plan to take a shovel with you and sit in the hole! :11: )

Your ppO2 is 1.58 at 130, and if you remained there for 30 minutes, your OTU's would be 57.72, and your CNS percentage would be 66.67. Not a problem unless you plan another dive on the boat, in which case a 90 minute SI would have you down to 33% on your CNS clock, and good to go.

(All figures per IANTD Technical Diver Encyclopaedia by Tom Mount.)

 

[SDAnderson]

NN II or NOAA Nitrox 32 or EANx 32 has an MOD of 130 fsw. I have had no problems diving it on the Spiegel, with the sand at 130.

Your exposure time is limited, with a single 80, especially since you will want to look at as much of the boat as you can. (I assume here, that you don't plan to take a shovel with you and sit in the hole! :11: )

Your ppO2 is 1.58 at 130, and if you remained there for 30 minutes, your OTU's would be 57.72, and your CNS percentage would be 66.67. Not a problem unless you plan another dive on the boat, in which case a 90 minute SI would have you down to 33% on your CNS clock, and good to go.

(All figures per IANTD Technical Diver Encyclopaedia by Tom Mount.)

OK, call me a sissy-boy, but 1.60 for a dive to 130 feet that the current can turn into a serious working dive is closer to the edge than I'm going to wander without very good cause, even in warm water. 1.40 (or even 1.20 in cold water if the dive is going to involve exercise) for the dive and 1.60 for the deco seems reasonably reasonable to me. I know that some disagree, but some always do...you just know there's a deep air diver out there reading this thread and laughing his...decoweenie off.

 

[KeyLargoBrent]

trying to plan ouut my dive on the spiegel grove, any suggestions on what mix. I was thinking EAN30 or 29. This assumes i dont drop below 110' is there much im missing by sacrficing that extra 20 ft? ill be diving from a boat so ill have 2 dives to make probably with a short SI so i cant max out my O2 exposure on the 1st dive

Most of the good stuff is now above 110'. The aft gunnels are about 100' deep. A MOD of 110' allows adequate shelter from deep currents from one end of the Spiegel Grove to the other. The sand is at about 130'. The wooden well deck is at about 120'. The foredeck is at about 90'. And the top (exposed) deck is at about 60'. Enjoy!

 

[BigJetDriver]

OK, call me a sissy-boy, but 1.60 for a dive to 130 feet that the current can turn into a serious working dive is closer to the edge than I'm going to wander without very good cause, even in warm water. 1.40 (or even 1.20 in cold water if the dive is going to involve exercise) for the dive and 1.60 for the deco seems reasonably reasonable to me. I know that some disagree, but some always do...you just know there's a deep air diver out there reading this thread and laughing his...decoweenie off.

No, I wouldn't call you a "sissy boy". A diver's choice of personal conservatism levels is just that, a personal choice, and not subject to criticism!

My point was simply that, to get to that level in the case presented, he would have to drop to the sand and remain there, which seems unlikely.

Just as a note of interest, we set 1.3 ppO2 on our CCR's almost all of the time for working dives.

Rob

 

[Kosh]

Reefman,

How is the diving now that she is turned upright? I'll be down there on Sept. 10 diving the Grove in the afternoon (going out with DiversCityUSA) if anyone is interested.

iv'e got 10 dives on the spiegel since it turned upright, and use a 30 to 32 mix. there's need, in my opinion, to descend to the sand(approx 130ft), as the majority of the sea life is between 70 and 110ft(primarily from the stern to midships).


reefman
key largo

 

[Orlando Eric]

I am still waiting for winter time when all the birds fly home.....