100m dive

[Superlyte27]

Definitely have helium in the deco gas below 30m. I got very powerfully narc'ed to the point I had to grab a wall when I made a switch from 12/65 to 32% at 36m a couple of years back.

I would also second using 21/35 instead of 32% and make that first switch at 58m, it'll give you a deco gas you can switch to deeper.

Also, how long is the dive plan? I personally don't like doing anything in the open ocean that's more than 3 hours in length -- conditions can change too quickly.

And what he said...
Jumping from lots of helium to no helium: no estas bein

 

[Fibonacci]

Seeking advice for my first dive to 100m - I'm using iDeco Pro... ~snip~

Other than being able to say you've dived to 100m... what is actually down there?
Scarpa Flow wrecks?
Seems to involve a LOT of risk and complexity for a non-commercial dive...

 

[legal.diver]

Superlyte27 - thanks for the advice!

Fibonacci - completely agree - there isn't much down there, however, for me it's depth progression as i'd much rather progress inland before moving to the open ocean for reasons stated by Kensuf previously.

 

[KenGordon]

He says it is an inland site. I guess Dorothea. A couple of dozen people have died there.

100m OC quarry dive? Really? On twin 12s? Having to ask on the internet which deco gasses to use?

I live in London, want to meet in a pub to discuss whether this is a good idea?

 

[legal.diver]

KenGordon - always happy to listen / learn from divers who are more experienced / qualified than me. In any event, there are many different combinations of deco gases and even more opinions on which is the ‘ideal’ mix so all I’m looking for is an open discussion on a potential dive plan.

Appreciate everyone’s input so far.

 

[EireDiver606]

I have no business being here but I have some sincere questions.

1. Is it normal for others to get recommendations for the dives that they’re planning?

2. Should you be doing these dives if you need help planning them?

3. Twin 12s for 100m? What about twin 15s?

 

[PfcAJ]

I have no business being here but I have some sincere questions.

1. Is it normal for others to get recommendations for the dives that they’re planning?

2. Should you be doing these dives if you need help planning them?

3. Twin 12s for 100m? What about twin 15s?

1: yes it’s good to learn and get opinions.

2: need help and want help are different

3: agree

 

[Kevrumbo]

My Open Circuit Depth Consumption Rate (DCR) at 90msw was a whopping 20bar/min on a single 13L Alu Tank -and that was with no physical activity at depth, just floating relaxed with neutral buoyancy.

So with double 12L cylinders with an initial fill of at least 232bar, be advised that at 100m depth with ten minutes bottom time, you will be at most having roughly half your bottom mix gas supply remaining. . .

 

[Superlyte27]

My Open Circuit Depth Consumption Rate (DCR) at 90msw was a whopping 20bar/min on a single 13L Alu Tank -and that was with no physical activity at depth, just floating relaxed with neutral buoyancy.

So with double 12L cylinders with an initial fill of at least 232bar, be advised that at 100m depth with ten minutes bottom time, you will be at most having roughly half your bottom mix gas supply remaining. . .

Based on your consumption, not his.

 

[Kevrumbo]

Based on your consumption, not his.

OP stated a nominal bottom time of 12min to 13min at 100m, so the above DCR is a reasonable guesstimate . . . You savvy?