dumpsterDiver
Banned
- Messages
- 9,003
- Reaction score
- 4,656
- # of dives
- 2500 - 4999
Today I was solo diving in around 180 ft on a large steel ship wreck located on uniform flat bottom. The wreck is sitting perpendicular to the prevailing current. Today the current was running around 3 kts (my best estimate). I was dropped about 600 feet upcurrent of the wreck and I swim downward as fast as I can and drift into the wreck.
I was carrying a reel with 500 feet of line and three floats. I hooked the reel off immediately upon reaching the wreck. Obviously I was pinned down by the current and could only move around inside the wreck.
The top of the wreck is around 160 feet deep. After the dive, I slowly ascended from 160 to around 100 feet depth in a time of probably 4 minutes. I had planned to do a deep stop at around 100 feet. Typically I do my ascents without kicking much and carefully ride my buoyant BC on ascent. Since I was wearing a very thin suit (1.5 mm) and a large steel tank, I need no lead and since I have very little suit to compress, I do not have to add or dump a lot of air from the BC during the dive. The ascent from 160 to 100 was normal, just flying through the water watching the fish fly by.
Anyway, when I got to 100 foot depth, I was a LONG way from the wreck. Soon after reaching that depth, I was caught in a pretty strong down current. My bubbles were going DOWN (even large quarter size bubbles). I was solo and it was a little disorienting since at this depth I could not see the bottom or the surface, even though the visibility was around 70 feet. I watched the computer and realized that even though I had not vented any air from the BC, I was starting to descend (along with my bubbles). I could see large sheets of bubbles, forming linear shapes moving downward 20 feet away from me and all around me too.
Initially, I tried to power out of the situation and began kicking upward, but it didnt seem to be changing my depth at all. I then decided (with a 30 min deco stop ahead of me) that I didnt want to exert myself. I inflated my BC a bunch, slowed my kicking and just watched the computer. Within maybe 30 seconds I was again making my way toward the surface and the bubbles stopped moving down and swirling around me. When I reached around 90 feet or so, I dumped all the extra air and resumed a normal uneventful ascent.
The last time I experienced something like this was around 10 years ago and my buddy and I were getting violently banged into each other and it was pretty scary since we had loaded spearguns and I had an explosive tip on my gun. The previous time, it was much more intense, so this time it was not particularly worrisome.
Ive done this same dive many dozens of times and only had this happen twice.
I was wondering if other people have experienced similar down drafts behind wrecks? I figure it is a large scale turbulent cell that is thrown off the wreck since it has vertical walls that extend around 20 feet off the bottom. Obviously, I am very familiar with turbulent cells being formed inside the walls of the wreck and directly in the lee of the wreck. This is very common and expected.
I would not do a dive like this at night, but if this were to happen at night, it would be very disorienting. Also, I was very happy to have sufficient excess air capacity in my BC to float out of the cell.
I was carrying a reel with 500 feet of line and three floats. I hooked the reel off immediately upon reaching the wreck. Obviously I was pinned down by the current and could only move around inside the wreck.
The top of the wreck is around 160 feet deep. After the dive, I slowly ascended from 160 to around 100 feet depth in a time of probably 4 minutes. I had planned to do a deep stop at around 100 feet. Typically I do my ascents without kicking much and carefully ride my buoyant BC on ascent. Since I was wearing a very thin suit (1.5 mm) and a large steel tank, I need no lead and since I have very little suit to compress, I do not have to add or dump a lot of air from the BC during the dive. The ascent from 160 to 100 was normal, just flying through the water watching the fish fly by.
Anyway, when I got to 100 foot depth, I was a LONG way from the wreck. Soon after reaching that depth, I was caught in a pretty strong down current. My bubbles were going DOWN (even large quarter size bubbles). I was solo and it was a little disorienting since at this depth I could not see the bottom or the surface, even though the visibility was around 70 feet. I watched the computer and realized that even though I had not vented any air from the BC, I was starting to descend (along with my bubbles). I could see large sheets of bubbles, forming linear shapes moving downward 20 feet away from me and all around me too.
Initially, I tried to power out of the situation and began kicking upward, but it didnt seem to be changing my depth at all. I then decided (with a 30 min deco stop ahead of me) that I didnt want to exert myself. I inflated my BC a bunch, slowed my kicking and just watched the computer. Within maybe 30 seconds I was again making my way toward the surface and the bubbles stopped moving down and swirling around me. When I reached around 90 feet or so, I dumped all the extra air and resumed a normal uneventful ascent.
The last time I experienced something like this was around 10 years ago and my buddy and I were getting violently banged into each other and it was pretty scary since we had loaded spearguns and I had an explosive tip on my gun. The previous time, it was much more intense, so this time it was not particularly worrisome.
Ive done this same dive many dozens of times and only had this happen twice.
I was wondering if other people have experienced similar down drafts behind wrecks? I figure it is a large scale turbulent cell that is thrown off the wreck since it has vertical walls that extend around 20 feet off the bottom. Obviously, I am very familiar with turbulent cells being formed inside the walls of the wreck and directly in the lee of the wreck. This is very common and expected.
I would not do a dive like this at night, but if this were to happen at night, it would be very disorienting. Also, I was very happy to have sufficient excess air capacity in my BC to float out of the cell.
