Do I need Nitrox?

[rottielover]

The cost eveyone is talking about is that it's typically in the neighborhood of 4 or 5 bucks more for a tank of EAN than for an air fill.. I've typically seen prices like $5 for an air fill, $8 or $10 for EAN ... Depending on where your getting your fills, you could possibly be doubling your cost for gas.

I was going to say that O2 exposure might be of concern depending on how many dives per day, over several days, but I dont' have my tables on me right now, and I really don't think you'd hit the O2 exposure limits that shallow.

Personally I think Air is your better option on such shallow dives, cheaper, easier, etc.

It would be a dif. story if your planned depth was deeper, as has been stated already.

All that being said, I don't think that you'll be disappointed with a Nitrox class and cert if you find a good instructor. My wife and I did our Nitrox just cause we wanted to have the option. Getting a nitrox cert doesn't me that's all you can ever dive again

Oh, and no, you should have to get your reg's or bc or anything serviced special for nitrox, nearly all the newer stuff out nowdays is OK with up to 40% O2 mix. You should double check to be sure, usually the website of the manufacter will tell you.

 

[rottielover]

Opps, I forgot to address your question on the 100-120 cu. foot tanks.

If all that are avalible are Nitrox tanks in that size, why not get your cert and ask for EAN 21% ?

I think people tend to forget that you can fill a Nitrox tank with "air" as long as the air used is "clean for O2" (O2 clean air?, forgot the exact termonology)...

People take EAN say 36% mix, breath it down to 500psi, then top off the tank back to 3000 psi with "air" (EAN21). You have to re-analyize that gas mix, but I think it would end up around 24 or 26% mix then (something like that).

Bottom line, is that you can get 21% mix (AIR) in a nitrox tank, without having to re-O2clean the tank again, as long as your fill station is using the proper equipment.

All this should be explained better in a full Nitrox course. My wife and I did our's a couple months ago...

 

[Jason Ooi]

Hi UB,

• 25ft NAUI Dive table will consider dept 40ft
• 2 hrs dive at dept 25ft ?
• What is your SAC?
• 2 hours at depth 25 ft from NAUI Dive Table is 40 ft 130 minute go to group K
• 1 hours SIT go to group I, 40 ft AMDT is 29 minute RNT 101
• Nitrox dive at 25 ft? Are you EANx Diver?

Why 2 hours dive at dept 25 ft what is your objective?

Jason

I have been doing some beach dives lately. My typically dive with the following profile:

~ 2hrs with a max depth of ~20-25ft
~ 1 hr surface time
~ 2nd dive at 2hrs with a max depth of ~20-25ft
~ Using tanks (80 cu ft) with air

My computer shows no problem with my nitrogen level (Aeris Atmos AI). I recently decided to check my tables and per NAUI's recommendation - for dives less than 40 ft I use the 40 ft table which indicated I exceeded the limits.

Should I switch to Nitrox to be safe?

Any feedback is appreciated

Thanks
UB

 

[moxie]

Nitrox does cost more. It's not unusual these days to pay $12 or more extra for a nitrox tank rental on a charter. Filling your own tank is somewhat less but still a lot more than just for air. I always dive nitrox when I can get it, but I usually don't dive all shallow profiles like yours. If money's no object, go for it. Can't hurt.

 

[ClayJar]

My LDS charges less than $5 (with tax) for an air fill, but $15 for Nitrox. They really need a membrane system or something so they can get the price down, and I'd be delighted to pick up an 130cf tank for Nitrox.

 

[UB]

Hi UB,

• 25ft NAUI Dive table will consider dept 40ft
• 2 hrs dive at dept 25ft ?
• What is your SAC?
• 2 hours at depth 25 ft from NAUI Dive Table is 40 ft 130 minute go to group K
• 1 hours SIT go to group I, 40 ft AMDT is 29 minute RNT 101
• Nitrox dive at 25 ft? Are you EANx Diver?

Why 2 hours dive at dept 25 ft what is your objective?

Jason

[*]2 hrs dive at dept 25ft ?
[*]What is your SAC?
Jason

The max depth is ~25 ft - alot of the dive is in the 18-21ft range. I only indicated the max depth since this is the depth I use for the air tables. Never calculate my SAC - I'll remember to do that.

[*]2 hours at depth 25 ft from NAUI Dive Table is 40 ft 130 minute go to group K
[*]1 hours SIT go to group I, 40 ft AMDT is 29 minute RNT 101
Jason

I did the same calculation and arrived at the same results. That is why I was concerned, I violated the air tables although my computer indicated I did not have a problem.

Why 2 hours dive at dept 25 ft what is your objective?
Jason

They are beach dives in Florida where you can not get more than 25ft max without a boat or scooter. I am usually taking photos, fishing watching, artifact hunting ..etc.

 

[Blackwood]

The max depth is ~25 ft - alot of the dive is in the 18-21ft range. I only indicated the max depth since this is the depth I use for the air tables.

Which air tables are you diving? I don't remember ever seeing any that have a column for 25 feet...

 

[rawls]

No.

No...

 

[Jason Ooi]

I do some calculation for you...
1 hours SIT is too short..dive safe
Why don't take CC rebreather you don't have to face problem

The max depth is ~25 ft - alot of the dive is in the 18-21ft range. I only indicated the max depth since this is the depth I use for the air tables. Never calculate my SAC - I'll remember to do that.

If say; your SAC 11 L/min used 11lt tank depth 8m time 120 minute Nitrox 21 .38ppo2 295 bar Impossible

used 15 lt tank SAC 11 L/min time 120 minute Nitrox 21 .38 ppo2 217 bar

I did the same calculation and arrived at the same results. That is why I was concerned, I violated the air tables although my computer indicated I did not have a problem.

Optional ....You can choose used NAUI dive table or computer calculation....there are two deferent calculation

 

[PerroneFord]

I do some calculation for you...
1 hours SIT is too short..dive safe

You're kidding right? :shakehead