dschonbrun
Contributor
I think there have been lots of info on doubles options and tank sizes, so I won't go into any detail there.
If you have a low SAC, and your buddy also has an equally low SAC, then it's possible for the two of you to use physically smaller tanks with less overall volume... but it may not be easy to find a shop that rents that equipment for your certification.
In order to get certified in Advanced Nitrox (IANTD) for example, you'll need to run doubles with a manifold, plus at least one side-slung (most students have to run 2, for a three gas training dive [bottom, Mid-O2-Deco, High-O2 Deco]). I used twin Steel LP 100's, and 2 AL80's for sides. The key reason is that in Decompression diving, you can't surface without risk of serious injury or death, so you bring at least twice the amount of gas you actually need; in case of an equipment failure by you or your buddy. If you're unable to physically carry this much equipment, you have 2 options. First, you can dress at the edge of the boat while seated on your bottom (calm seas only) or in the water (wholly or partly). I've had several students with bad backs Don and Doff in the water... It's tricky, but can be learned. I've also seen side-slungs handed to divers who are already in the water. There are risks with this option, as fully loaded tanks are negatively bouyant.
The second option, which may not be as palatable, is to avoid diving that requires this much weight of equipment. No one likes limitations... but my instructor (Steve Tippets) had a simple first test for anyone who really wanted to get into Tek... you had to walk in full gear (doubles plus 2 side slungs) all the way to the end of the pier, get into the water safely under your own power (down a ladder), and then swim out 200 yds in full gear before starting the dive. Physical fitness does play a role in diving, and that only increases with dive complexity and range.
If extended range and increased safety are things you want to learn, there are several options without adding an insane amount of weight on your back. One of these might be a CCR. Another option would be to dive a single 100 and two 40's for Deco... but limiting your dive plans to ensure you could safely decompress and surface in the event of a failure.
Hope this helps.
If you are seriously interested in learning to dive doubles, contact Dive-Tech in Grand Cayman.
If you have a low SAC, and your buddy also has an equally low SAC, then it's possible for the two of you to use physically smaller tanks with less overall volume... but it may not be easy to find a shop that rents that equipment for your certification.
In order to get certified in Advanced Nitrox (IANTD) for example, you'll need to run doubles with a manifold, plus at least one side-slung (most students have to run 2, for a three gas training dive [bottom, Mid-O2-Deco, High-O2 Deco]). I used twin Steel LP 100's, and 2 AL80's for sides. The key reason is that in Decompression diving, you can't surface without risk of serious injury or death, so you bring at least twice the amount of gas you actually need; in case of an equipment failure by you or your buddy. If you're unable to physically carry this much equipment, you have 2 options. First, you can dress at the edge of the boat while seated on your bottom (calm seas only) or in the water (wholly or partly). I've had several students with bad backs Don and Doff in the water... It's tricky, but can be learned. I've also seen side-slungs handed to divers who are already in the water. There are risks with this option, as fully loaded tanks are negatively bouyant.
The second option, which may not be as palatable, is to avoid diving that requires this much weight of equipment. No one likes limitations... but my instructor (Steve Tippets) had a simple first test for anyone who really wanted to get into Tek... you had to walk in full gear (doubles plus 2 side slungs) all the way to the end of the pier, get into the water safely under your own power (down a ladder), and then swim out 200 yds in full gear before starting the dive. Physical fitness does play a role in diving, and that only increases with dive complexity and range.
If extended range and increased safety are things you want to learn, there are several options without adding an insane amount of weight on your back. One of these might be a CCR. Another option would be to dive a single 100 and two 40's for Deco... but limiting your dive plans to ensure you could safely decompress and surface in the event of a failure.
Hope this helps.
If you are seriously interested in learning to dive doubles, contact Dive-Tech in Grand Cayman.
