Will a LP 85 Steel tank last for my typical dive?

[scubamikey]

Will a Worthington LP 85 Steel tank last for my typical dive? I’ll be using it mostly in upstate NY lakes, mostly “blowing bubbles” in the local lakes during the summer. Probably lots of time at 30’, probably not more than 60’ except for a few trips to the St. Lawrence to view wrecks. I like the characteristics of the tank (2400+10%, steel, etc.) but I want to make sure it will hold enough air so I’m limited by my NDL, not the air I have left. I'm 6'1" and 220lbs, I’ll have a SS bp/w and a wetsuit. Due to the water temp I may not want to be in for more than 45-60 minutes anyway. Obviously I’m new to diving, but figuring the time I got with the AL80’s in class I think the LP85 will work. My LDS does do HP fills, but if LP will work for me, it’s cheaper and safer, etc… Your thoughts or other recommendations?

 

[tstonedvr]

The 85 is far superior to the AL80....more gas, better trim, less weight to add (if any)and if your shop will do it you can if needed get a good overfill.
Yarg

 

[The Kraken]

Depends upon your sac rate and average depth of dive.

Just for kicks and giggles, let's just say that your sac rate in that water is .65 cfm.

You mention 30' and 60', so let's just take the average, 45'.

45' equates to an ATA of 2.4, so therefore you will use 2.4x.65cfm of air per minute = 1.56 cfm.

The NDL for a 45' dive is 100 minutes (The Wheel).

Your consumption on a LP 85 @110% will give you approximately a 60 minute dive time with no reserve.

the K

 

[scubadobadoo]

Depends upon your sac rate and average depth of dive.

Just for kicks and giggles, let's just say that your sac rate in that water is .65 cfm.

You mention 30' and 60', so let's just take the average, 45'.

45' equates to an ATA of 2.4, so therefore you will use 2.4x.65cfm of air per minute = 1.56 cfm.

The NDL for a 45' dive is 100 minutes (The Wheel).

Your consumption on a LP 85 @110% will give you approximately a 60 minute dive time with no reserve.

the K

Excellent post Kraken!

IMHO the answer to the question is yes it will be enough as long as you are within the limits you defined and especially as you get more experience. At first though, you will likely have to keep a close eye on you air spg.

I have two steel HP 80's and love to dive them as does my wife. I also like my steel HP 100 but I only use it for longer, deeper dives. Have fun and DSAO!

 

[daniel f aleman]

The Worthington LP 85 is a favorite tank for the freshwater cenotes dives down here. Great tank, but keep it in fresh water.

 

[rjack321]

My LDS does do HP fills, but if LP will work for me, it’s cheaper and safer, etc…

LP tanks are no more or less safe than HP tanks. They all have enough potential energy to really to some damage and hurt you.

 

[DEEPLOU]

Depends upon your sac rate and average depth of dive.

Just for kicks and giggles, let's just say that your sac rate in that water is .65 cfm.

You mention 30' and 60', so let's just take the average, 45'.

45' equates to an ATA of 2.4, so therefore you will use 2.4x.65cfm of air per minute = 1.56 cfm.

The NDL for a 45' dive is 100 minutes (The Wheel).

Your consumption on a LP 85 @110% will give you approximately a 60 minute dive time with no reserve.

the K

The fella says he is newbe, 220 lb and 6' 1". So .65 cf/m is very generous from what i have seen.

But as you say, that is the only way to tell how far a particular tank will take you.

 

[cummings66]

Reading between the lines, he's not got any dives beyond the OW dives because of the phrase "Obviously I’m new to diving, but figuring the time I got with the AL80’s in class" I'd say that this tank will not let him hit the NDL's at this point in time because his SAC is even higher than guessed at.

If that's his goal starting out then he's going to need a larger tank. For my money I'd just start diving and the SAC will get lower and he'll hit the NDL's with that tank eventually.

A good way to answer it is to post his last dive specs so we could figure his SAC and thus answer the question with certainty.

 

[The Kraken]

The following tanks, with 500 psi left in reserve, will yield these dive times at 50':

130 CF
SAC / Time
0.40 / 110
0.50 / 88
0.60 / 74
0.70 / 63
0.80 / 55
0.90 / 49

120 CF

0.40 / 101
0.50 / 81
0.60 / 68
0.70 / 58
0.80 / 51
0.90 / 45

Al 80 CF
0.40 / 64
0.50 / 51
0.60 / 42
0.70 / 36
0.80 / 32
0.90 / 28

the K

 

[scubamikey]

Thanks, this has been really helpful. I really like the dimensions and weight of the LP 85, but I'm wondering if I should go a little bigger. Seems I could still do a lot of fun diving with the LP85, but once I get a little more experience I may want a larger size. Hard to decide if I should stick with LP or get a HP tank.

Here's the horrible info from the OW class. Data is moderately accurate. Keep in mind we were doing our drills, not just calmly drifting along. Also, I found that 3 large breaths would help relieve anxiety, so I used a lot of air that way. That should subside before long. Also, I should be better weighted and happier in my new gear (none bought yet).

Gear:
Apeks basic regs
al80
seaquest pro qd+ bc
26 lbs weight
7mm suit

Dive 1
22 feet
20 min
used 1300 psi

Dive 2
24 feet
15 min
used 1000 psi

Dive 3
24 feet
20 min
used 1300 psi

Dive 4
24 feet
16 min
used 1100 psi

You're going to tell me I need a tank like the one in the yard that holds propane, aren't you?