Steel doubles in the tropics

[TSandM]

I started out with a set of 72s, and I don't like them in part for the reasons they'd probably work for you -- they aren't very negative! Full, they are about 140 cubic feet of gas, so about 9 pounds of usable. Empty, as doubles, they are at best neutral or even a little positive, so your maximum value for being negative at the beginning of the dive is about 10 lbs or so. I believe it is generally held that most people can swim that much up (I know I can).

Gilldiver's caveats are spot on. But $100 for an assembled set of doubles is dirt cheap. (I paid $350 for each of my sets of 72s.)

 

[captain]

AL80's could be acquired for a similar price resulting in the most appropriate configeration IMO. I have doubled LP85's listed here and TDS which I would breakup selling valve (Halcyon) and bands (Highland)...

The double 72's will have much better buoyancy characteristics. I have dived them in salt water with no BC or weights with no problems

 

[Ed Palma]

Thanks for the replies guys, they've really got me thinking...

They're old Dacor LP72s. Can't seem to find much buoyancy data or if they have a liner or such. Asked the seller to send me the numbers on the shoulder just to give me some idea of their ages, as well as better photos.

 

[boulderjohn]

Fairly soon there will be posts here saying "No steel doubles with wet suits" but that is ignorance, it should be "don't use some steel doubles with wet suits."

In the course of my cave training, I dived with three other divers other than my instructor. All were wearing steel doubles, and I was the only one diving dry. I am told that one of the most famous cave divers in the Hogarthian system (hint) does pretty much all his diving these days wet.

On the other hand, agencies like UTD will not allow wet suits with steel doubles in its courses.

 

[halocline]

I would guess that even the most hardened supporters of the "no steel doubles w/wetsuit" mantra would make an exception for LP72s, as they are far less negative than the majority of steel tanks.

 

[txapacheguy]

In the course of my cave training, I dived with three other divers other than my instructor. All were wearing steel doubles, and I was the only one diving dry. I am told that one of the most famous cave divers in the Hogarthian system (hint) does pretty much all his diving these days wet.

On the other hand, agencies like UTD will not allow wet suits with steel doubles in its courses.

Please pardon my ignorance on this matter, but I am not sure I understand why doubles with a wetsuit would be frowned on or forbidden. Is it due to the inability to inflate a wetsuit for extra buoyancy if needed??? Thanks in advance for the info!!!

Edit: I meant steel doubles.

 

[boulderjohn]

Please pardon my ignorance on this matter, but I am not sure I understand why doubles with a wetsuit would be frowned on or forbidden. Is it due to the inability to inflate a wetsuit for extra buoyancy if needed??? Thanks in advance for the info!!!

Good guess!

The fear is that when you are fully weighted and have a wing failure, you will have trouble swimming up all that weight. Inflating your dry suit can help.

 

[Scott L]

Please pardon my ignorance on this matter, but I am not sure I understand why doubles with a wetsuit would be frowned on or forbidden. Is it due to the inability to inflate a wetsuit for extra buoyancy if needed??? Thanks in advance for the info!!!

Diving in a wetsuit with double steel cylinders is frowned upon by most due largely to the loss of bouyancy of most brands of neoprene at depth which coupled with a BCD failure could spell problems. What is interesting to me is the different tactics of lift bag usage in such situations. Lot's of varying opinions. Would be a nice thread to start in the near future...

 

[Rhone Man]

Please pardon my ignorance on this matter, but I am not sure I understand why doubles with a wetsuit would be frowned on or forbidden. Is it due to the inability to inflate a wetsuit for extra buoyancy if needed??? Thanks in advance for the info!!!

I think the key point is that steel doubles and wetsuits are sometimes considered a bad idea (for bouyancy reasons). Aluminum doubles and wetsuits are a pretty common site in the Caribbean.

I had a chance to buy steel doubles but bottled it after reading various threads on SB and assembled a set of aluminum doubles instead (at greater expense).

 

[txapacheguy]

Makes sense... Thanks for the info!!! I hope to live somewhere eventually that will actually enable me to use such equipment on a routine basis.