repetitive deco dive plan

[Deal Me In]

ok, here is my problem. i'm scheduled to do my mandatory decompression dive next week. as part of the class i have to complete a dive plan. now, my problem is on the second dive. on the plan, my RNT is 9 minutes. the second dive calls for a dive to 100 feet for 25 minutes and then i have to plan the deco and gas consumption.

now, i'm assuming that what i have to do is add the 9 minutes into the dive plan on the second dive. so that i would plan the dive based on 100 feet at 40 minutes. i'm using tables for this part of the question. is this correct.

the next question is for people that use dive voyager. i have it and i can't figure out how to make it compute repetitive dives. a buddy told me that it won't do it but i find this hard to believe.

thanks for your time.

 

[roakey]

Sometimes things need to be said, sorry...

You're taking a deco class and you don't have confidence in your ability to use the tables?

Roak

 

[MikeFerrara]

ok, here is my problem. i'm scheduled to do my mandatory decompression dive next week. as part of the class i have to complete a dive plan. now, my problem is on the second dive. on the plan, my RNT is 9 minutes. the second dive calls for a dive to 100 feet for 25 minutes and then i have to plan the deco and gas consumption.

now, i'm assuming that what i have to do is add the 9 minutes into the dive plan on the second dive. so that i would plan the dive based on 100 feet at 40 minutes. i'm using tables for this part of the question. is this correct.

the next question is for people that use dive voyager. i have it and i can't figure out how to make it compute repetitive dives. a buddy told me that it won't do it but i find this hard to believe.

thanks for your time.

Voyager will do repetative dives. I lost the hard drive that I had it on so I can't give you step by step directions but it does them.

 

[Deal Me In]

no roakey, i have complete confidence in myself to use tables. my instructor asked me to see if i could figure it out on my own. i can't get in touch with him at the moment. the reason that i'm taking the class is to learn how to the things that i don't understand. i thought maybe somebody on here would give me some help. thank you very much for yours.

thanks for you time.

 

[IndigoBlue]

Maybe Chickdiver could help. She is licensed and insured to answer students' questions like this.

There are probably 2000 divers on this board that could easily answer the question, but they are not all tech instructors.

Of course, I think the idea is for the student to figure this out on his/her own.

The issues involved are extreme exposure vs RNT residual groups, minimum surface interval time, maximum depth on repetitive dives, to name a few. I hope you went over those topics in the class and/or in the reading.

 

[MikeFerrara]

If you were doing a no-stop dive what would you do with the RNT?

 

[Uncle Pug]

my instructor asked me to see if i could figure it out on my own.

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i thought maybe somebody on here would give me some help.

 

[IndigoBlue]

If you were doing a no-stop dive what would you do with the RNT?

Mike just gave you a really big clue. There are still other issues, however. Maybe your instructor wants to see how many additional considerations you can come up with, in your planning. Good luck.

 

[MikeFerrara]

You mean figuring out who to as doesn't count?

Most classes use a text book that explains this stuff and some tables even have the directions right on them.

You don't suppose that the instructors just trying to find some one to explain it to him do you?

 

[Deal Me In]

mike, thank you for helping me. i understand that you are trying to lead me in the right direction. since you are i will tell you my thinking and you let me know if i'm on the right track.

i've never planned a decompression dive, hence my taking the class. now i know that if it is a no stop dive that i have to subtract the RNT from the allowable bottom time. however, i'm know going in that it will be a decompression dive so i'm not worried about the NDL. but the RNT has to be accounted for, in the case 9 minutes. my thinking is that since i would subtract the 9 minutes for a no stop dive, i would account for it by adding it to the second dive and planning the deco based on the planned depth and time plus the 9 minutes of RNT.

for the record the first place that i looked was my textbook, in the case the TDI decompression procedures manual. they describe how to allow for the RNT in no stop dives but not in planned deco dives.

if my thinking is wrong please lead me in the right direction but i can't think of another way to account for the nitrogen from the first dive.

if it helps the planned profiles are as follows.

1st dive -- 130' 20 min.
1 hour SI
2nd dive -- 100' 25 minutes

thanks for your time