A comment on down currents from a personal experience - also in Raja Ampat. We had hit patchy strong head currents that I was not prepared to swim against, so signaled to my guide that I was going up, which he OKed. As I went up the reef I hit a strong head current that I could not swim against so I grabbed what I could. Another dive guide with his group saw me and came over to move me sideways out of the strong current. It was like a rip on a surf beach and the rule there is don't fight it, move sideways and hopefully get out of it. It certainly worked for me, but it clearly was nowhere near as strong as that experienced in this unfortunate incident. I didn't feel scared at any stage, but was glad I had plenty of air! My air consumption rate was through the roof.