No Deco limits on deep (~100') double dips

[tursiops]

on 32% tables say 98 feet for 20 min. 60 min interval. 98 feet for 12 min. it is always interesting to see how the tables compare to the software models like the one posted above.

I don't know what tables you used, but the PADI RDP for 32% says NDL is 30 mins for first 100 ft dive, then after 60 min SI you get 16 mins at 100 ft.
Going to only 90 ft changes that to 35 mins followed by 18 mins.
The key is not to do dive #1 all the way to your NDL.
If the first dive to 100 ft on 32% backs off just 6 mins from NDL, so the BT is 24 mins instead of 30, then the second dive to 100 ft (after 60 min SI) has an NDL of 19 mins.
Another way to extend the second dive is to be first in on Dive #1, get out, and be last in on Dive #2; that is, get a SI longer than 60 mins. For example, if the first dive is 30mins=NDL to 100 ft, but the SI is 80 mins instead of 60 mins, your second dive to 100 ft has an NDL increase from 16 mins to 19 mins.

 

[boulderjohn]

On March 1 I did a double dip on the RSB-1 off Pompano Beach with a 51 minute surface interval. The first dive used EANx 30, and the second used EANx 32. The first dive was 111 feet max for 34 minutes total run time, and the second dive was 110 feet max for 34 minutes total run time. I used the Buhlmann algorithm with GF 55/85 and surfaced after my SurfGF was 70, meaning I probably took a little longer than the standard safety stop.

 

[rick00001967]

PADI 32% tables say 35 min and then 18 min @ 90 ft (with hr si)? Even 100 ft on the 1st dive is 30 min?

my tables also have a max ndl f 30 min on dive one to 98 feet. i just used 20 min as an example to leave more timeon dive 2.

 

[rick00001967]

I don't know what tables you used, but the PADI RDP for 32% says NDL is 30 mins

i never said 20 min was the max did i?

 

[tursiops]

i never said 20 min was the max did i?

No, no you didn't. My bad for assuming...but then saying 98 ft also threw me off.
What tables were you using?

 

[rick00001967]

No, no you didn't. My bad for assuming...but then saying 98 ft also threw me off.
What tables were you using?

ssi combination tables (air/32/36). they show air depth to every 10 feet, so the 32% and 36% depths are odd numbers

 

[tursiops]

ssi combination tables (air/32/36). they show air depth to every 10 feet, so the 32% and 36% depths are odd numbers

Thanks. But 98 isn't odd!

 

[Wibble]

30m/100ft dive plan. 32% backgas. 60mins bottom time and 20 to 30mins of deco on 80% or 100% according to the computerS (varies depending upon the actual dive profile you dived)

So much easier.

 

[DogDiver]

MOD for 36% is 95'......

36% is a pretty hot mix for 95 feet. Have dove those wrecks and it is too easy for novice divers to find themselves in the sand. If you have ever seen a diver tox out on a hot mix it is gruesome.

 

[rhwestfall]

There is a heck of a lot of superstructure, and a hull is pretty boring....