zamburinha
Contributor
I thought I would share a recent experience that really drove home a few lessons and made me very happy about the training me and my team mates had received. Some background. The site was in Bunaken island (Sulawesi, Indonesia), known for its incredible wall dives. The plan was for a technical dive with a maximum depth of 50 meters (164ft), average 45m (148ft), with a bottom time of 25 minutes and 30 minutes deco (deco is padded, but that is a different story). We were a group of 5, all of us with double alu 80s containing trimix 18/45 for bottom gas, 3 of the group were carrying an additional alu 80 for bottom gas with the same mix (with the intention of not touching their back gas). All of us had an alu 80 with nitrox 50 for our deco gas. We had all been to this particular site before at recreational depths, and we have each 10s of dives in the Bunaken area, so we felt reasonably confident about our plan.
The dive started very relaxed. The visibility was very good and we quickly descended to our target depth along the wall. The bottom flattened out somewhat and we started to drift with a light current along a sandy slope. As the dive progressed, the current started to pick up, still carrying us along the wall/slope. Twenty minutes into the dive at a depth of around 45-43 m (148-141ft), we went over a small ridge and suddenly were in a raging downwards current. We had expected a little of it given the topology of the site, but the strength caught us off gard. In a few seconds we had descended 10m and only because we managed to hold on to the reef. Although I am normally a prety efficient swimmer, I had to fight extremely hard to reach the wall, and as I held on to a giant sponge with all my strength and watched my bubbles rocket downwards into the blue, I had a moment to asses the situation. My depth was around 53m (174ft) and my gas was 90 bar (a full fill is 200bar or 3000psi). One diver was slightly above me and another slightly below, both holding on to the reef. My other 2 team mates where well below (I later learned one of them hit 64m, 210ft) and were trying to reach the reef. As luck would have it, it was the people who got sweept down the furthest that had the extra gas (they were practising their recently acquired tech1+ cert that allows them an extra bottle). Myself and the diver just above me only had our back gas and we were huffing and puffing just to hold on to that wall. It immediately became apparent that we needed to head for the gas switch as quickly as possible as we were going through our reserves fast. I took a few seconds to bring my breathing under reasonable control and focussed on climbing up that reef. It took significant focus to go up with a reasonably efficiency both in breathing and speed. As we reached around 24m (gas switch is at 21m), the downcurrent changed to a sideways current, we let go of the reef and proceeded to perform the switch while drifting away from the wall. The gas switch proceeded without apparent incident and we did our deco as we floated away from the island rapidly. As we ascended after 30 min we realized we had drifted far away from the island and we were in the middle of a channel and could not see the boat any more (although we knew where it should be). We had launched an SMB during deco, but we were too far away for them to see it, and they were expecting us along the wall, rather than a few miles away in an orthogonal direction. The strongest swimmer in our group then decided to swim towards the entry point and try to get the boat's attention. After swimming for 2 hours, he reached the boat and 20 minutes later the boat reached us.
Some more information. At the end of the dive I had 60 bar (870psi) of backgas left. My other team mate with only backgas had actually run out exactly at the switch and had nothing left in his tanks. My teammates that were breathing bottom gas from a stage sucked it dry and consumed a significant fraction of their backgas. We all consumed more than usual on deco.
Lessons learnt:
-Strong down currents are more dangerous and scarier than I thought. In this particular dive it was exacerbated because we were towards the end of the dive and near our maximum depth.
-Never, ever be tempted to go beyond minimum gas, it is there for a very good reason.
-Taking time to take control and assess a situation is worth it, even if it seems like you have no time to spare.
-Good team mates trained in the same set of procedures are an incredible resource. It got hairy, but nobody lost their composture and we took the time to check on each other as soon as we could, helping to calm everybody down.
-In ocean dives, carry a BIG SMB. We were all carrying SMBs, but they were the tiny versions and I had to confess I had a large one sitting in my dive bag in the hotel ... I was not the only one
. Ultimately we were lucky to be close enough to be able to reach land by swimming, but a few boats passed reasonably close and did not see us with our punny little orange smbs, so we could have been stranded for quite a while longer.
-It is not a stupid idea to take a cap or cloth to protect you from the sun if there is a possibility of being lost. Needless to say none of us had one and we got burnt to different degrees under the blazing Indonesian sun.
Thinking about the dive, I feel it was kept under control, but I also realize that we were at the edge of what we could handle. Had one more thing gone wrong, I am not sure things would have turned out fine. Definitively gave me some things to ponder about.
The dive started very relaxed. The visibility was very good and we quickly descended to our target depth along the wall. The bottom flattened out somewhat and we started to drift with a light current along a sandy slope. As the dive progressed, the current started to pick up, still carrying us along the wall/slope. Twenty minutes into the dive at a depth of around 45-43 m (148-141ft), we went over a small ridge and suddenly were in a raging downwards current. We had expected a little of it given the topology of the site, but the strength caught us off gard. In a few seconds we had descended 10m and only because we managed to hold on to the reef. Although I am normally a prety efficient swimmer, I had to fight extremely hard to reach the wall, and as I held on to a giant sponge with all my strength and watched my bubbles rocket downwards into the blue, I had a moment to asses the situation. My depth was around 53m (174ft) and my gas was 90 bar (a full fill is 200bar or 3000psi). One diver was slightly above me and another slightly below, both holding on to the reef. My other 2 team mates where well below (I later learned one of them hit 64m, 210ft) and were trying to reach the reef. As luck would have it, it was the people who got sweept down the furthest that had the extra gas (they were practising their recently acquired tech1+ cert that allows them an extra bottle). Myself and the diver just above me only had our back gas and we were huffing and puffing just to hold on to that wall. It immediately became apparent that we needed to head for the gas switch as quickly as possible as we were going through our reserves fast. I took a few seconds to bring my breathing under reasonable control and focussed on climbing up that reef. It took significant focus to go up with a reasonably efficiency both in breathing and speed. As we reached around 24m (gas switch is at 21m), the downcurrent changed to a sideways current, we let go of the reef and proceeded to perform the switch while drifting away from the wall. The gas switch proceeded without apparent incident and we did our deco as we floated away from the island rapidly. As we ascended after 30 min we realized we had drifted far away from the island and we were in the middle of a channel and could not see the boat any more (although we knew where it should be). We had launched an SMB during deco, but we were too far away for them to see it, and they were expecting us along the wall, rather than a few miles away in an orthogonal direction. The strongest swimmer in our group then decided to swim towards the entry point and try to get the boat's attention. After swimming for 2 hours, he reached the boat and 20 minutes later the boat reached us.
Some more information. At the end of the dive I had 60 bar (870psi) of backgas left. My other team mate with only backgas had actually run out exactly at the switch and had nothing left in his tanks. My teammates that were breathing bottom gas from a stage sucked it dry and consumed a significant fraction of their backgas. We all consumed more than usual on deco.
Lessons learnt:
-Strong down currents are more dangerous and scarier than I thought. In this particular dive it was exacerbated because we were towards the end of the dive and near our maximum depth.
-Never, ever be tempted to go beyond minimum gas, it is there for a very good reason.
-Taking time to take control and assess a situation is worth it, even if it seems like you have no time to spare.
-Good team mates trained in the same set of procedures are an incredible resource. It got hairy, but nobody lost their composture and we took the time to check on each other as soon as we could, helping to calm everybody down.
-In ocean dives, carry a BIG SMB. We were all carrying SMBs, but they were the tiny versions and I had to confess I had a large one sitting in my dive bag in the hotel ... I was not the only one
. Ultimately we were lucky to be close enough to be able to reach land by swimming, but a few boats passed reasonably close and did not see us with our punny little orange smbs, so we could have been stranded for quite a while longer.-It is not a stupid idea to take a cap or cloth to protect you from the sun if there is a possibility of being lost. Needless to say none of us had one and we got burnt to different degrees under the blazing Indonesian sun.
Thinking about the dive, I feel it was kept under control, but I also realize that we were at the edge of what we could handle. Had one more thing gone wrong, I am not sure things would have turned out fine. Definitively gave me some things to ponder about.
Just wow...!
