Learning doubles w/ Twin HP 120s?

I'm interested in taking some tech classes in the future. As many have suggested, I would like to practice diving doubles for awhile before I sign up. I currently have two Sherwood HP 120s I use as singles when drysuit diving. They are long (31.9"), have a diameter of 7.29" and weigh 41.5 lbs (empty). I'm 6'6" and really like the length as singles. I'm wondering if these tanks are too much for someone just starting doubles?

Take it easy and do the first couple of dives shallow. If you can find a mentor it will make a world of difference. There shouldn't be any reason why you can't dive the 120's. Also make sure that your buddy knows what they are doing with your valves just in case. Valve drills are most important in my book but they can take time.

I agree with Wally. My first dive in my LP85's wasn't a very smooth one. The buddies I was with were newly minted cave divers. They knew I had 50+ dives in drysuit, but 0 in doubles, but thought it shouldn't be a big deal. The dive plan was to go to abut 100ft & skim over the bottom, up an old haul road of the quarry, BIG MISTAKE. Not knowing the negative characteristics of those tanks, I agreed (I had dove that path many times in singles). When we went to descend, I foolishly released all the air in my wing. I almost immediately found myself in an uncontrolled descent. Also, having only dove singles before, I was trying to descend feet first, instead of in a sky diver's position, so had the tanks trying to pull me over backwards. All that task loading was a bit too much for me. I really didn't have time to equalize my ears, I was really lucky they pretty much equalized themselves. Long story short, I got myself stopped at 95ft. By that time I was in a state of near panic,.... completely stressed. As my buddies caught up with me, I decided to abort the dive & began my ascent. My buddies stayed right there with me & helped me along back to the surface. Once there, I decided to sit out for a while & collect myself. My buddies went on with their planned dive. After a few hours, I found another buddy who was interested in shallow diving. I did another 30 dives in those doubles before even thinking about going deep. I got familiar with those tanks during that time. At that time there was a very good OW instructor who knew of what had happened to me & helped to guide me back to the deep in the doubles. Since then I have been improving & learning more about them. After a year, I now have control of them, instead of the opposite. As Wally stated, start shallow, go with someone with some experience, take your time to get familiar with them.

Another option would be to take an Intro to Tech or equivalent. Personally I would get a few shallow dives in and get a few things lined out..trim, weight, new gear config..and then try a class. Personally I hate a stressful class. Just my $.02.

crpntr133:

Another option would be to take an Intro to Tech or equivalent. Personally I would get a few shallow dives in and get a few things lined out..trim, weight, new gear config..and then try a class. Personally I hate a stressful class. Just my $.02.

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That's my plan. I would like to dive the doubles this fall as I still have a few months before the lakes here freeze. The sequence of course work in either Intro to Tech or GUE Fundamentals followed by Tech 1 (Naui Adv. Nitrox, Deco and Helitrox). I would do the intro class in the spring and then practice some more before the Tech 1 class.

I have several friends that dive a local lake every Tuesday/Thursday night. Some dive doubles and are cave certified, so I would have some guidance.

I would eventually buy some smaller tanks to give me some other options when diving, I just can't afford it right now.

bikefox:

That's my plan. I would like to dive the doubles this fall as I still have a few months before the lakes here freeze. The sequence of course work in either Intro to Tech or GUE Fundamentals followed by Tech 1 (Naui Adv. Nitrox, Deco and Helitrox). I would do the intro class in the spring and then practice some more before the Tech 1 class.

I have several friends that dive a local lake every Tuesday/Thursday night. Some dive doubles and are cave certified, so I would have some guidance.

I would eventually buy some smaller tanks to give me some other options when diving, I just can't afford it right now.

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Your 120's will work fine, especially for someone your height. Find your experienced doubles buddies and start in the shallow waters. Have fun.

Sounds like you have a plan.

bikefox:

I'm interested in taking some tech classes in the future. As many have suggested, I would like to practice diving doubles for awhile before I sign up. I currently have two Sherwood HP 120s I use as singles when drysuit diving. They are long (31.9"), have a diameter of 7.29" and weigh 41.5 lbs (empty). I'm 6'6" and really like the length as singles. I'm wondering if these tanks are too much for someone just starting doubles?

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I used PST 120's when I took my tech class. I'm 6' 1" and at 180 lbs. I had all the tanks I needed and then some. I dive HP 100's now. They're just a little easier for me to pack around. As others have said find someone who dives doubles and get a few tips on setup, balance and control. Do very easy dives even some pool dives to get use to the balance and weight. You shouldn't find it that much different moving through the water. Practice staying horiziontial and you'll have a lot of fun. Enjoy.

I'm going to disagree and say 120s are not the right tanks. They are too big for most ocean diving and most cave divers prefer other tanks. Back in the day, they were also frowned on by the Tech 1 crowd so you may have an issue there if you go that route.

bikefox:

I currently have two Sherwood HP 120s I use as singles when drysuit diving. They are long (31.9"), have a diameter of 7.29" and weigh 41.5 lbs (empty). I'm 6'6" and really like the length as singles. I'm wondering if these tanks are too much for someone just starting doubles?

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I am 5'11" and 200lbs. I doubled up two PST HP120s as my first doubles rig. Before starting my tech class, I took them to the quarry for several shallow drysuit dives, then took them off the coast for several wetsuit dives in the 85-90' range, both times with buddies diving singles. They worked fine. Biggest challenge I had was finding the optimal wing. I found the dual Super to simply be too big, and ultimately ended up with a Halycon Explorer 55 as my preferred wing, after trying a Dive Rite Rec, a Classic, and an Oxycheq Signature 50. My dive buddy is 6'6" and uses a dual Super with his 120s and loves it.