I had another weekend of tech training (AN+DP) this past weekend up at Hyde's Quarry, in MD. It was cold and we were diving dry. Me, with double (back mount) HP120s and an AL40 slung on the left. Saturday was okay, but not great. The previous time out (which was my first time diving doubles and dry at the same time), I had learned that I could not reach my valves in my drysuit. So, for this time, I lowered the bands 1.5" to try and make them easier to reach. On Sat, I learned that I still could not reach them, but now they seemed too high. Other than not being able to complete a valve drill, the 2 dives on Sat went okay. My buoyancy was far from perfect, but it wasn't terrible. I have 2 classmates and our instructor said we did pretty well on buddy skills and team diving. And we did well on getting in a star (triangle?) formation and staying level and together as we deployed SMBs and did a staged ascent and gas switch (still using air for everything, at this point) on both dives. His biggest criticism of me on Saturday (aside from needing to get my reach to my valves sorted out) was that sometimes during a task my legs would droop and I would get out of trim by an unacceptable amount. Not vertical, but probably somewhere around 30-ish to maybe even 45 degrees.
Sunday was a different story, though. I adjusted my bands back up 3/4", to see if I could split the difference on being able to reach my valves. I could barely reach them. But, the effort it took for the right post and isolator was so much that my left hand was tired and cramping up (even though it wasn't doing much of anything most of the time) before I could complete the left side shutdown. And on top of that, the worst part was that for whatever reason, my buoyancy control was completely out the window. Maybe it was from being tired. I don't know. I was tired anyway, and then the attempted valve drill at the start of Sunday's first dive got me more tired. My buoyancy was okay during the (failed) valve drill. But after that, it was like I was the worst OW student ever. Every time I got tasked with anything, I would just drop like a rock. Often, 10 feet. Even just doing a swim it seemed like as soon as I got myself adjusted, I would start to float up. Then I would let some air out of my BC and then start to drop like a rock. I felt like a complete basket case for the whole first dive. And I was diving exactly the same everything as the day before.
During the debrief, it was noted that I was a complete basket case for buoyancy and my instructor asked how much weight I was carrying. I told him I had my 6 # SS BP and the 8# bolt-on weight plates, for 14 #, total. He and the AI seemed very surprised and suggested that I probably did not need any of the 8# weight plates at all. I was somewhat confident that I did. But, I was so bad in the water on dive 1 that I decided to try the next dive with those plates removed.
I started the dive with roughly half full tanks for dive 2 (on Sun). I was way too light. I was able to get down, but it was a bit difficult to get started down. Then, midway through the dive, we were following a line and gradually ascended to about 15'. I started to float up from there (not on purpose). So I attempted to dump some air from my BC, using the corrugated hose, and no air came out. Meanwhile, of course, I'm accelerating towards the surface. I finally flipped myself completely vertical and some more air came out of my BC then and I was able to stop my ascent and then fight my way back down.
Also, during the whole dive, if I stopped finning for even a second, I would start rotating immediately into a head down position. I understand this to be a classic symptom of being underweighted. And, just to be clear, for this dive, I had on minimally fluffy undergarments - only a couple of layers of Lavacore, in fact. And I was only putting just enough air in my drysuit to make the squeeze be not painful. Because of the trim problem, every time I kicked, the first part of the kick stroke was spent just kicking my head end back up to horizontal and then the last part of the kick stroke would propel me forward a little bit.
At the end of the dive, we were at 20-something feet with a plan of deploying SMBs, ascending to 20', doing a gas switch, and then getting out. I was also attempting to inflate my SMB using my 2nd stage, for the first time. Normally, I've been inflating it by catching exhaust from 2nd stage instead. As soon as I started trying to do that, I started to float up and then that turned into another runaway ascent and I ended up at the surface.
The uncontrolled ascents weren't that big of a safety concern, in the circumstances. That quarry is only 55' at the bottom and we were mostly swimming around between 20 and 30 feet during that dive. I didn't hold my breath and I didn't shoot up and out of the water. I wasn't worried about getting bent from it. It was just very frustrating.
All said and done, I calculate that double HP120s at half full will become roughly 6.5# more buoyant to the positive when they are at 500 psi. This leads me to think that putting that 8 # back on is probably just about exactly the right weighting for the configuration I was diving. And, like I said, my buoyancy seemed okay on Saturday. I think I might need to experiment with moving the weight around a little bit to get my trim better, but the amount of weight seemed okay.
Anyway... All in all, a very humbling day.
Thanks for letting me vent. :depressed:
Sunday was a different story, though. I adjusted my bands back up 3/4", to see if I could split the difference on being able to reach my valves. I could barely reach them. But, the effort it took for the right post and isolator was so much that my left hand was tired and cramping up (even though it wasn't doing much of anything most of the time) before I could complete the left side shutdown. And on top of that, the worst part was that for whatever reason, my buoyancy control was completely out the window. Maybe it was from being tired. I don't know. I was tired anyway, and then the attempted valve drill at the start of Sunday's first dive got me more tired. My buoyancy was okay during the (failed) valve drill. But after that, it was like I was the worst OW student ever. Every time I got tasked with anything, I would just drop like a rock. Often, 10 feet. Even just doing a swim it seemed like as soon as I got myself adjusted, I would start to float up. Then I would let some air out of my BC and then start to drop like a rock. I felt like a complete basket case for the whole first dive. And I was diving exactly the same everything as the day before.
During the debrief, it was noted that I was a complete basket case for buoyancy and my instructor asked how much weight I was carrying. I told him I had my 6 # SS BP and the 8# bolt-on weight plates, for 14 #, total. He and the AI seemed very surprised and suggested that I probably did not need any of the 8# weight plates at all. I was somewhat confident that I did. But, I was so bad in the water on dive 1 that I decided to try the next dive with those plates removed.
I started the dive with roughly half full tanks for dive 2 (on Sun). I was way too light. I was able to get down, but it was a bit difficult to get started down. Then, midway through the dive, we were following a line and gradually ascended to about 15'. I started to float up from there (not on purpose). So I attempted to dump some air from my BC, using the corrugated hose, and no air came out. Meanwhile, of course, I'm accelerating towards the surface. I finally flipped myself completely vertical and some more air came out of my BC then and I was able to stop my ascent and then fight my way back down.
Also, during the whole dive, if I stopped finning for even a second, I would start rotating immediately into a head down position. I understand this to be a classic symptom of being underweighted. And, just to be clear, for this dive, I had on minimally fluffy undergarments - only a couple of layers of Lavacore, in fact. And I was only putting just enough air in my drysuit to make the squeeze be not painful. Because of the trim problem, every time I kicked, the first part of the kick stroke was spent just kicking my head end back up to horizontal and then the last part of the kick stroke would propel me forward a little bit.
At the end of the dive, we were at 20-something feet with a plan of deploying SMBs, ascending to 20', doing a gas switch, and then getting out. I was also attempting to inflate my SMB using my 2nd stage, for the first time. Normally, I've been inflating it by catching exhaust from 2nd stage instead. As soon as I started trying to do that, I started to float up and then that turned into another runaway ascent and I ended up at the surface.
The uncontrolled ascents weren't that big of a safety concern, in the circumstances. That quarry is only 55' at the bottom and we were mostly swimming around between 20 and 30 feet during that dive. I didn't hold my breath and I didn't shoot up and out of the water. I wasn't worried about getting bent from it. It was just very frustrating.
All said and done, I calculate that double HP120s at half full will become roughly 6.5# more buoyant to the positive when they are at 500 psi. This leads me to think that putting that 8 # back on is probably just about exactly the right weighting for the configuration I was diving. And, like I said, my buoyancy seemed okay on Saturday. I think I might need to experiment with moving the weight around a little bit to get my trim better, but the amount of weight seemed okay.
Anyway... All in all, a very humbling day.
Thanks for letting me vent. :depressed:
