Post by VKPost by -hhBottom line is that when you watch someone nearly drown because they
didn't have one
How did that happen? Am curious.
Long story short, the current carried us south, but our chase boat
went north. We ended up with a 30+ minute float before they picked us
up.
The surface conditions were fairly non-benign: we were in a short
rough & breaking chop that had been aggrivated by near-shore
reflections off of some cliffs & rocks. We couldn't do a shore exit
because of these cliffs/rocks, so we were obligated to stay off and
drift float.
The diver in question was in a Wing with a rental AL80 didn't have
problem for the first ~15 minutes, as they merely stayed on their
regulator and sucked their tank dry instead of breathing surface air.
When they went to change over to surface air, the breaking waves and
such prevented a minimal inflation level (which would have normally
caused only a slight 'face down'), so because of the rough seas, they
had inflate a bit more, to literally keep their nose above water more
than half the time. The same erratic and rough waters prevented the
approach of rolling up onto one's back, plus I found that this also
reduced one's situational awareness as to where the cliffs and
submerged rocks were - - the group as a whole subconciously stayed too
close to the rocks than they should have (I probably lead 4 or 5 "okay
everyone swim back offshore" exercises).
The lesson learned from all of this is that the amount of effort that
a floater needs to expend is relatively trivial for a short float, but
as the float duration increases, this can lead to rapid fatigue. For
this diver, they "weren't in trouble" until they had sucked their tank
dry and had to rely on 'surface supply', which because of the surface
conditions, wasn't particularly easy, as the weight of the gear caused
a significant lag in the short wave period, so we were literally
dunking to the point of 'mask underwater' on nearly every wave pass.
It might not be the types of surface conditions that one encounters
every day, but when it happens, it can quickly get to the point where
the diver needs to ditch his gear in order to have a viable surface
float orientation that does not cause a high exertion level.
-hh