Those 300(+) foot dives............

[texdiveguy]

I am wanting to hear from those of you 'whom have' executed pinnacle dives in the 330ft (+) range on open circuit,,,,your impressions/dive prep/location/dive profile/objective of the dive/gases/team make-up......blablabla. Thanks

 

[karstdvr]

It has been awhile since I did a 330' dive. When I do a dive like that I will dive 12/50,and use for my deco 32%,50/50,and O2,very rarely will I use an intermediate trimix just because that is an extra bottle. I often will carry bigger tanks for deco other than 40s such as 80's or 72's depending on dive duration to make sure to have reserve gas-I spend a lot of time on gas planning to make sure I have all contingencies covered. Team make up is usually a close group of people I dive with that have experience at this depth too. My impression: has to be something really worth seeing because I am going to pull a lot of deco for a fairly short bottom time. I don't do a lot of deep dives like this anymore,because lately with high helium percents I have a nystagmus that makes reading guages very difficult;I think this may be a mild symptom of HPNS

 

[Johnny Richards]

My deep dives are typically in the 250- 300' range with divers I know well in either Eagle's Nest or Diepolder II and III. Backgas is dependent on depth in ranges of 14/40 to 12/50 with decompression gases of EAN32, EAN50 and oxygen. I use a Dive Rite He computer for decompression status and time with dive specific backup tables and bottom timer in the event of a computer failure. Team members are closely matched on gas and the dive plan is well discussed and understood prior to the dive. Every team member clearly understands:

1. None of us have anything to prove to ourselves, the others or anybody else; and

2. Any of us may call the dive at any time for any or no reason, no questions and no recriminations.

I have made the 5 1/2 hour round trip to Eagle's Nest on a couple of occasions with the dive called before the team entered the water.

Decompression times are long in comparison to bottom times, but the whole routine- mixing gas, travel time, decompression time, etc.- is well worth it to dive a site usually not inhabited by other divers and see very beautiful caves mostly unaffected by the usual diver damage.

These are complex dives with a great deal of preparation time, but the rewards are worth it to me and my usual dive team members.

Johnny
www.cavediving.com

 

[texdiveguy]

It has been awhile since I did a 330' dive. When I do a dive like that I will dive 12/50,and use for my deco 32%,50/50,and O2,very rarely will I use an intermediate trimix just because that is an extra bottle. I often will carry bigger tanks for deco other than 40s such as 80's or 72's depending on dive duration to make sure to have reserve gas-I spend a lot of time on gas planning to make sure I have all contingencies covered. Team make up is usually a close group of people I dive with that have experience at this depth too. My impression: has to be something really worth seeing because I am going to pull a lot of deco for a fairly short bottom time. I don't do a lot of deep dives like this anymore,because lately with high helium percents I have a nystagmus that makes reading guages very difficult;I think this may be a mild symptom of HPNS

Hey thanks for your story....sorry to hear of the Nystagmus. What are you baseing these feelings on that you may be suffering from HPNS....just curious....not prying.

 

[karstdvr]

Hey thanks for your story....sorry to hear of the Nystagmus. What are you baseing these feelings on that you may be suffering from HPNS....just curious....not prying.

Subjective feeling that it could HPNS related since it only happens with high % helium. It hasn't stopped me from diving deep,just do more compensatory things.