Diving Doubles

[chemdog]

I've never dove with doubles before but I just watched a video in a sub-forum and noticed that the dive times for a team diving doubles was less than an hour. In this situation was the purpose for doubles for air redundancy? Why do people dive doubles?? When do people transition from diving singles to doubles? Thanks!!

 

[Peter Guy]

In this situation was the purpose for doubles for air redundancy?

Who knows? Since you didn't put a link to the video, the question doesn't appear to be answerable.

Why do people dive doubles??

a. Redundancy for overhead (technical) diving;
b. More gas thus more BT;
c. More stability;
d. Single tanks are empty; and
e. To look cool

When do people transition from diving singles to doubles?

a. When they want to;
b. When they have a need to; and
c. When their wife (or significant other) lets them get a set.

 

[Dr Wu]

No idea. I did not see the video.



Safety and redundancy. Extended bottom time. To avoid switching tanks between dives.



Depends on the person. Some people wait hundreds of dives. Some a dozen or so.

 

[chemdog]

here is the link to the thread: http://www.scubaboard.com/forums/norcal/380686-hurricane-bay.html

 

[TSandM]

Well, run time (total dive time) isn't a good measure of what the dive was.

For example, I can do an hour-long dive in Puget Sound and stay within NDLs and not go deeper than 20 feet, and use very little gas.

Or I can go down to 150 feet and do 25 minutes of bottom time, and when I finish my deco, I'll have been in the water . . . one hour! But at 150 feet, I want redundancy, and the "rock bottom", or gas required to get me and a buddy to our gas switch at 70 feet, is a large volume!

People often think technical dives are long dives, but in the shallower ranges, and if you want to keep your deco to what you're comfortable doing in cold water, they really may not be.

As already stated, people use doubles because they want redundancy (at any depth and dive time). They also use them for deep dives where the rock bottom becomes onerous on the single tanks that are available (see Errol Kalayci's post from earlier this year about Florida diving). Some people use them because they don't like swapping out tanks when doing more than one dive in a day. And some of us use them because all the single tanks are in the shop getting fills . . .

 

[RU4SKUBA]

Personally I'd check the Advanced forums for stuff like this, since this isn't general diving discussion. However, diving doubles usually reflects someone's desire to improve their fundamentals in that gear set rather than a genuine need for that kind of gas volume.

Like the doc said, its hard to answer the question without understanding the circumstances of the dives. Doing a series of penetration dives in the Mayan Riviera --even in shallow water-- has a requirement for a lot of backup gas, the kind twin steel 130s can provide.

Diving a shallow lake with doubles usually means practicing valve and S-drills, air-sharing ascents, trim and weight distribution adjustments, and gear testing. These folks also LOVE to talk about their rigs and HATE it when people touch it without permission.

 

[TSandM]

Having watched the video, I'd say at least some of the purpose of the dive was to continue gaining comfort and skill in the configuration. That's as good a reason to dive them as any.

 

[chemdog]

Thanks for the clarification everyone!

 

[craracer]

In addition to the well-stated reasons mentioned above, doubles can replace an entire day at the gym doing cardio or training legs/back.

Lugging a set of HP steel 95's and two deco bottles from my vehicle to waters edge, while wearing a big garbage bag over a sleeping bag (dry suit) is good fun! I love the feeling of asphyxiation

 

[CamG]

Greetings chemdog most of the reasons are clearly covered in the afore mentioned threads.
For me it was the environments I wanted to dive, the planned dives demanded it.
So I started to train with doubles slowly building experience moving into more advanced dives.
They are heavy and at times a pain to move around but well worth the hassle when you are in a wreck at depth or cave environment.

The issues that drive people to dive doubles are simply the dives demand it.
Gas management is reality to the advanced dive realm not just to look cool.
But a nice cleanly configured set of doubles is a sexy thing indeed!

CamG Keep Diving....Keep Training....Keep Learning!