Trim with 3 deco cylinders?

[Jack Hammer]

@stuartv , IIRC, you were pretty vocal not too long ago about using best mix for all technical dives, remixing as needed, and it being better overall as opposed to a gas that works in a wider range of depths. With your upcoming class has this changed?

ps: not a jab, curious if your stance has changed.

 

[stuartv]

Day 1 is done. I have some issues to deal with tomorrow. But, one positive thing I can say is that 2 bottles slung on the left and the third on a leash behind didn't really seem very difficult. Rotating the 40 to the front and an 80 to the back didn't seem like a big deal. The 80 was full of 21/30. Hopefully, it will be even easier once I've actually breathed that down during deco, so the 80 is lighter. We were on a platform that was at around 50', I think. My self-critique is that I held my depth, but I did move around a little bit. But, it was the first time I ever tried that, so I think I'll do better next time. This way of carrying 3 cylinders is VASTLY more comfortable (to me, anyway) than the way I was trying it last weekend. It wasn't even that bad to swim. But, swimming with a heavy 80 on the least instead was more challenging. I could feel it hanging right down between my legs, so every frog kick or back kick was somewhat limited.

@stuartv , IIRC, you were pretty vocal not too long ago about using best mix for all technical dives, remixing as needed, and it being better overall as opposed to a gas that works in a wider range of depths. With your upcoming class has this changed?

ps: not a jab, curious if your stance has changed.

I have always maintained that (to ME) Best Mix means the best mix when you factor in ALL the relevant information, not just the depth. If you want to use a ppO2 of 1.4 as your max and you're planning a dive to 140, you'd pick an FO2 that gives you 1.4 at 140 - UNLESS you know that you might have to divert to a site that is at 160. In that case, the "best mix" is one that will give you a ppO2 of 1.4 at 160. If you do get on the site at 140, oh well. It's not the MOST efficient gas you could be using. But, it is still the Best Mix, when you factor in all the information you have.

I think that is very different than how the Standard Gas devotees like to characterize diving with best mix. It also seems superior (to ME) to saying "well, if we're going to 140', we would choose Gas X, which is good for anywhere from 100 - 150. But, it we might have to divert to a site that is at 160, then we're going to use a gas that is good for anything from 150-200." Why use a gas that is good for 200 on a site that is only at 140? How is that better than using a gas that is only good for a max of 160?

Anyway.... In this case, 10/50 is not the gas I would have chosen for 300'. But, I'm not the instructor, so I'm using what I'm told (as long as I think it is adequately safe, which, in this case, I feel like it is).

 

[sturgis69rider]

diving with twins most of my life twin 50's 72s 80's 100's 120's i started with twin steel 72 in 1974 i went down for the march of dimes marathon 23 hrs in a pool they just put new tanks in the water for you .to kill time we tried riding bike , playing chess /checkers watch tv .. made almost $3800 time under water i used a lot of Vaseline on my hands and lips and feet it was bad

 

[stuartv]

Epilogue: I did a 250' dive and a 305' dive on the final days of class to complete my cert.

My issues with my trim were sorted out by switching from my SS BP and a tail weight to my Kydex BP and no tail weight at all. I started the first dive with the Kydex BP and a 3# tail weight and my feet were too "sinky". I ditched the tail weight altogether and then it was fine. I was diving with 2 cylinders slung on my left and 1 on a tail leash. Maybe that also helped (versus having all 3 cylinders slung up front). My trim did change throughout the dives, based on use of the cylinders and, for example, going from a full 40 of O2 on a leash behind me to a partly empty 80 of 21/35 on the leash and the full 40 on my chest. But, those variations were easy enough to just "handle". Going to the Kydex and no tail weight was the key to a stable platform (for me).

 

[stuartv]

Oh, and, though it is off topic, since there was a bunch of discussion about using TX10/50 for a 300' dive, I will share this story. It reveals a screw-up or somewhat poor judgment on my part, but as I've said before, I'm not afraid to out myself here - especially if it somehow helps anyone else in the future.

On our final dive, yesterday, we hit 305'. Viz was great from 70' down to about 280 and then we dropped into a layer of bottom murk and viz was less than 10', I'd say. Our instructor was leading us. The plan was to hit the bottom by 13:00. That allowed time on the 60' ledge where we would be anchored to switch to back gas, clean up the travel gas cylinder, and swim to the edge of the ledge. Not necessarily the way to get the most bottom time, but we wanted to be conservative (versus, for example, switching to back gas and cleaning up while also descending). The day before, it took us until 16:30 to do the same thing and then drop to 250'. But, that was the first time we did it and the first time my buddy and I had really dived together (versus earlier class dives where we were diving with the instructor and doing skills at 60' - not really diving as a buddy team). We had talked through the first dive, sorted things out and felt good about getting to the bottom more quickly than the day before. And we did. We got to 300' at 11:00. Our plan was to start our ascent at 17:00. Not very long on the bottom, but we were constrained in our planning by the fact that I had only brought a 40 for O2 and we were only able to fill it to 2200psi after the first deep dive.

So, we got to the bottom, in crappy viz and started to swim. Almost immediately, I saw something and looked a little up and a little to the right and there was orange line floating there. Looking at my buddy, I saw that it was already starting to get wrapped around his feet. Fudge!! And I thought, "huh. That line looks new. And it's the same color as the line on my reel. Fudge!"

I had a newish (not too many dives on it yet) 400' reel, pre-rigged with an SMB clipped to my right waist D-ring. Except... not anymore. It was gone and I had no idea how.

I saw that our instructor was now in front of my buddy and already working the problem. I determined that I didn't care about trying to save the reel or the SMB (wherever that was - I never saw it), so I dug out my shears and swam up to my buddy's feet and started just cutting the line up. My buddy was stellar in his performance. He held totally still and kept his buoyancy. After the fact, I learned that my instructor had seen the line problem just before I did and it was coming from my reel, which was still clipped to me. The instructor unclipped it from my belt and I never even knew it. And, somehow, the line didn't get around me at all. My instructor got in front of my buddy and was trying to reel it up. He saw pretty much right away that things where too far gone for that and saw me cutting away at the back. On the boat afterwards, he said "I saw Edward Scissorhands back there, going to town." LOL! I was also watching the time and knew we still had several minutes left in our planned bottom time, so worked the problem at depth for the moment.

The instructor decided things were not where there was a simple and immediate fix, so at that point, he gave us the thumbs up and we started our ascent. At that point, the reel line was already cut, so he reeled in the last bit and clipped it off to himself. When we got back up onto the ledge and did our 2nd gas switch, the brake on the reel had loosened itself again and the line was coming unspooled again. My instructor pulled it back out and tried to get it reeled back in and secure again. It immediately started coming loose again. My buddy took it and tied a loop in the line and put that around the brake and tightened it all and that seemed to hold it. Meanwhile, my instructor was writing in his wet notes. When they both finished, the instructor took the reel back, clipped a noted into the gate of the double-ender on the reel and handed it all to me...

After it was all over, I was replaying how it all went and I can tell that I was definitely narced. I was functional. But, my situational awareness was definitely impaired. I am very glad that it all worked out without anyone getting hurt, or even causing us to have any variance from our schedule. Well, other than we began our ascent at 13:00, instead of 17:00. Planned runtime was 70 and we were out at 63, including about 4:00 of extra time on O2 at 10' at the very end (after my computer said I was cleared).

I will definitely not dive that deep again without a lot more helium. I think the way it went shows that I was "okay". But, I can tell that I was not "great", or even "really good" and, for diving deep, I want to be "great" in the future. That whole situation could have been a LOT worse and somebody dying because I simply didn't put enough helium in would be infinitely beyond stupid.

I said earlier the story reveals some personal shortcomings. What I mean by that is that, first, I splashed for a 300' dive with a reel/SMB setup that was not adequately secure. The SMB was only held to the reel by a bungee loop that is sewn to the SMB and which was around the SMB and the spool in the reel. It must have gotten knocked loose, so then the only thing holding it was the brake on the reel itself. The brake is clearly crap and loosened enough to let the line spool out and the SMB drop. I take responsibility for splashing with a reel/SMB rig like that. I should have seen the potential and rigged it in a way that was more secure. And, second, I didn't notice that it had come loose and was paying out line, nor did I even notice when my instructor came up behind me and took the reel off my belt. Another indicator of my level of narcosis.

So, I screwed up. Thankfully, in the end there was no harm, and I learned some valuable lessons for the future.

If anyone sees some other ways that I screwed up that I have not identified, feel free to point them out. I don't mind if you're brutal. I was there, and I'm here, to learn. A mistake that I don't learn from is an opportunity wasted....

 

[grantctobin]

Oh, and, though it is off topic, since there was a bunch of discussion about using TX10/50 for a 300' dive, I will share this story. It reveals a screw-up or somewhat poor judgment on my part, but as I've said before, I'm not afraid to out myself here - especially if it somehow helps anyone else in the future.

On our final dive, yesterday, we hit 305'. Viz was great from 70' down to about 280 and then we dropped into a layer of bottom murk and viz was less than 10', I'd say. Our instructor was leading us. The plan was to hit the bottom by 13:00. That allowed time on the 60' ledge where we would be anchored to switch to back gas, clean up the travel gas cylinder, and swim to the edge of the ledge. Not necessarily the way to get the most bottom time, but we wanted to be conservative (versus, for example, switching to back gas and cleaning up while also descending). The day before, it took us until 16:30 to do the same thing and then drop to 250'. But, that was the first time we did it and the first time my buddy and I had really dived together (versus earlier class dives where we were diving with the instructor and doing skills at 60' - not really diving as a buddy team). We had talked through the first dive, sorted things out and felt good about getting to the bottom more quickly than the day before. And we did. We got to 300' at 11:00. Our plan was to start our ascent at 17:00. Not very long on the bottom, but we were constrained in our planning by the fact that I had only brought a 40 for O2 and we were only able to fill it to 2200psi after the first deep dive.

So, we got to the bottom, in crappy viz and started to swim. Almost immediately, I saw something and looked a little up and a little to the right and there was orange line floating there. Looking at my buddy, I saw that it was already starting to get wrapped around his feet. Fudge!! And I thought, "huh. That line looks new. And it's the same color as the line on my reel. Fudge!"

I had a newish (not too many dives on it yet) 400' reel, pre-rigged with an SMB clipped to my right waist D-ring. Except... not anymore. It was gone and I had no idea how.

I saw that our instructor was now in front of my buddy and already working the problem. I determined that I didn't care about trying to save the reel or the SMB (wherever that was - I never saw it), so I dug out my shears and swam up to my buddy's feet and started just cutting the line up. My buddy was stellar in his performance. He held totally still and kept his buoyancy. After the fact, I learned that my instructor had seen the line problem just before I did and it was coming from my reel, which was still clipped to me. The instructor unclipped it from my belt and I never even knew it. And, somehow, the line didn't get around me at all. My instructor got in front of my buddy and was trying to reel it up. He saw pretty much right away that things where too far gone for that and saw me cutting away at the back. On the boat afterwards, he said "I saw Edward Scissorhands back there, going to town." LOL! I was also watching the time and knew we still had several minutes left in our planned bottom time, so worked the problem at depth for the moment.

The instructor decided things were not where there was a simple and immediate fix, so at that point, he gave us the thumbs up and we started our ascent. At that point, the reel line was already cut, so he reeled in the last bit and clipped it off to himself. When we got back up onto the ledge and did our 2nd gas switch, the brake on the reel had loosened itself again and the line was coming unspooled again. My instructor pulled it back out and tried to get it reeled back in and secure again. It immediately started coming loose again. My buddy took it and tied a loop in the line and put that around the brake and tightened it all and that seemed to hold it. Meanwhile, my instructor was writing in his wet notes. When they both finished, the instructor took the reel back, clipped a noted into the gate of the double-ender on the reel and handed it all to me...

View attachment 610659

After it was all over, I was replaying how it all went and I can tell that I was definitely narced. I was functional. But, my situational awareness was definitely impaired. I am very glad that it all worked out without anyone getting hurt, or even causing us to have any variance from our schedule. Well, other than we began our ascent at 13:00, instead of 17:00. Planned runtime was 70 and we were out at 63, including about 4:00 of extra time on O2 at 10' at the very end (after my computer said I was cleared).

I will definitely not dive that deep again without a lot more helium. I think the way it went shows that I was "okay". But, I can tell that I was not "great", or even "really good" and, for diving deep, I want to be "great" in the future. That whole situation could have been a LOT worse and somebody dying because I simply didn't put enough helium in would be infinitely beyond stupid.

I said earlier the story reveals some personal shortcomings. What I mean by that is that, first, I splashed for a 300' dive with a reel/SMB setup that was not adequately secure. The SMB was only held to the reel by a bungee loop that is sewn to the SMB and which was around the SMB and the spool in the reel. It must have gotten knocked loose, so then the only thing holding it was the brake on the reel itself. The brake is clearly crap and loosened enough to let the line spool out and the SMB drop. I take responsibility for splashing with a reel/SMB rig like that. I should have seen the potential and rigged it in a way that was more secure. And, second, I didn't notice that it had come loose and was paying out line, nor did I even notice when my instructor came up behind me and took the reel off my belt. Another indicator of my level of narcosis.

So, I screwed up. Thankfully, in the end there was no harm, and I learned some valuable lessons for the future.

If anyone sees some other ways that I screwed up that I have not identified, feel free to point them out. I don't mind if you're brutal. I was there, and I'm here, to learn. A mistake that I don't learn from is an opportunity wasted....

Thank you for the recap.

 

[RyanT]

Thanks for sharing Stuart! Quick question, where did you do your dives?

 

[stuartv]

Thanks for sharing Stuart! Quick question, where did you do your dives?

Lake Jocassee, South Carolina. Working out of the Lake Jocassee Dive Shop. I.e. diving off the LJDS boats.

If you know the lake, our dives were all on or off the Chinese Junk wall.

 

[NothingClever]

We can’t let that word ‘sinky’ go to waste. I think to memorialize it, we should dub you “Stuart Sinky Feet” .

Thanks for the real dive story.

Reading it was way, way better than watching yet another “demonstration quality” video that makes technical diving out to be some polished ballet.

 

[stuartv]

We can’t let that word ‘sinky’ go to waste. I think to memorialize it, we should dub you “Stuart Sinky Feet” .

But that was just 1 dive! The weekend before, I was Stuart Light Foot (which sucked way worse than sinky feet).

Now I have Goldilocks Feet...