Tiny Doubles and Tech question

[uncfnp]

Mselenaous and TSandM, I am extremely impressed by the doubles you have both been able to manage and thanks for your support and recommendations.

Sidemount is already a recurring theme. Definitely worth looking into more.

 

[halocline]

I started with double 72s, and I hated them, and hate them to this day. I cannot trim out the things, and honestly, they are not that much lighter than bigger tanks.

I remember you saying this a few years back and I was surprised because LP72s and LP85s are pretty similar in dimension and buoyancy characteristics. I used double 72s for a few years. But after renting double 80s in MX, I was also surprised at how much better they trim than 72s. Now I took apart the 72s and put together a couple of catalina 80s and I'm very happy with them. The 72s are wonderful single tanks.

Anyhow, back to the topic, I would suggest you really define what exactly your gas requirements are and then figure out the easiest way to satisfy them. My guess is that you'll end up going sidemount like many people these days. I'm used to manifolded doubles, but I do get the attraction to sidemount, especially for smaller women and/or difficult shore entries.

In general, you'll get more gas for the carry weight of a large single tank than anything else, so if it's just more gas you need, that's the way to go. If you need redundancy, look at sidemount first, if you like it, you're set. If not, I just don't see the practicality of anything smaller than 72s for doubles. Lots of vintage divers have small doubles set ups, but it's the 'cool' factor (especially with a center outlet manifold) not the practicality that makes those attractive.

 

[Tom Winters]

"Tiiiiiiiiiny doubles..." - you know, I can still hear Don Ho singing that song at the Hilton Hawaiian Village.

Figure out how much gas you need - then find the rig. You're small - you'd look like a munchkin next to me. THE best tanks I ever saw for smaller women are the venerable LP66 tanks judiciously overfilled. Oh wait... that's not allowed anymore.

Even filled normally, there's probably enough gas in one of those little puppies to let you outlast all the hosses diving with you.

I can carry giant pieces of furniture - it also means that I use a LOT of gas on a dive. Time after time after time, I've seen these leetle itty bitty women with a toy LP66 outlast me.

Now that said, twinned LP45's are about the coolest little set of doubles out there. LP85's start getting heavy. I have a set, and they are pretty snazzy, but it's been years since I used them. I just go with my HP120's that replaces my LP 125's that I ran at 4500psi. I had twin AL 80's a long, long time ago - they were ok. I like the steel weights better.

So you have lots of options...just try not to buy 'em twice getting it all right.

The RB is another path to trot. It can be a little pricey, and you can't harvest lobsters in Floriduh on one. You'll figure it out.

 

[TSandM]

I looked longingly at sidemount . . . but I'll warn you that in a lot of ways, taking two tanks to the water at once, on your back, can be easier than the whole mess involved in schlepping them individually and then putting them on in the water. Not to mention that backmounted doubles are much easier on boats.

 

[lucca brassi]

because we have shallow sea (average 15-20 m ; 33 max ) I want from single 18l to tiny doubles . I borrow them and test in pool ..... like , like ,like them very much

DBG 8,5l breit Doppelgerät 232bar - Konkav - Artikeldetailansicht - TEC-DIVING ONLINESHOP - Tauchausrüstung für Technisches Tauchen

but all other dives in normal doubles 2*12l /230 bar so if I want to stay and dive in group I have to switch . For both I use donut wing 44 lbs (20L) - perfect.

 

[rivers]

i'm 5'3 (first thing in the morning if I have a really good stretch before getting out of bed), but with an athletic frame. I dive twin 12L (which are about 100 cubic ft I think). No problems schlepping them about. The only issue i've had has been leaning too far back on a kitting up bench and looking like a turtle while everyone around me had a good laugh before helping me up.

 

[Trace Malinowski]

Many petite women I have trained liked AL80s, LP85s, LP95s and HP100s to start. For tech and cave training, the least amount of gas allowed in a set of doubles would be twin 72s or twin AL80s. When you learn to surf you start out with a long, thick board and work your way to shorter ones as you master the sport. In skydiving, you start jumping large canopies and work your way to smaller faster ones. In diving, we want to do the opposite by starting small, but keep the same principle of growing into equipment that requires more skill. Learning to dive in big tanks is like learning to surf on a short board. It can be done, but the process is more frustrating and time-consuming.

Most divers and instructors have no clue how to properly position tank bands and adjust harnesses. I can't tell you the number of divers who told me they had trouble diving doubles over the years only to be fixed in minutes with correct adjustment of harness and bands. This is made easier by using a single weave harness for the shoulders and waist and avoiding harnesses with multiple adjustment points. I normally start off with the bands placed all the way up flush with the break of the cylinders where they begin to curve toward the valves. Also, start with the plate centered on your back and the harness snug to the point where you can just insert three fingers underneath the straps, but you still can remove your tanks underwater by flipping them over your head. The manifold shouldn't be above your shoulder break when a buddy is looking at you face to face and underwater you should be able to have a full range of motion in your neck allowing you to get your head all the way back without uncomfortably contacting the manifold so that you are looking forward while lying in the prone position underwater. At this point, to achieve trim, the recipe is head back, chest to knees flat, pelvis at lowest point, butt tight keeping the thighs from dropping lower than your pelvis and fins flat. You find your sweet spot by moving your feet closer or farther away from your center of gravity for balance. Once all that is accomplished, you can decide if any slight modification to the position of the bands or the tightness of the harness need to be made.

In no time you can start small and dive 104s or 130s.

 

[rhwestfall]

nice informative post Trace!

 

[uncfnp]

The RB is another path to trot. It can be a little pricey, and you can't harvest lobsters in Floriduh on one. You'll figure it out.

No lobsters!? That settles it. No RB for me.

Great info guys. Lots of good information. Obviously, this isn't going to be a simple choice.

 

[djtimmy77]

Two of my dive buddies are female and did their ANDP on pumped up 98's with H-valves. They had similar goals as you, increasing safety on wreck dives.