Bobo wrote:
Every Spring and Summer, people drown on low-head dams. It's one thing
to accidentally end up in a low-head dam, but to do so intentionally is
madness and to do so without wearing a PFD is a death wish.

Even WITH a PFD, the recirculation and the aeration in a low-head dam
tailwater can easily drown you. They aren't called "drowning machines"
for nothing.

Dive-Rescue International has a training course about low-head dam
rescue. The bottom line is that it's a very low-probability rescue.
They show some helicopter rescue, a fire-ladder rescue, and, most
soberingly, an attempt by some public safety officials in a boat at the
site of a boating accident attempting to recover what they thought was a
swimmer but which turned out to be an unused PFD from the earlier
incident. I think one guy survived, by hanging on to the lower unit of
the overturned would-be rescue boat. We watched people die on that
video, and it was a very disturbing sight.

If you have lines off both shorelines you can ease an inflatable
"Zodiac" boat into the tailwaters. Another expedient is to take a large
line off a fire truck, inflate it with air from a SCUBA or a
firefighter's SCBA device, and push the inflated hose across the surface
to a swimmer -- but that swimmer would have to be awfully lucky, awfully
strong, and have a stationary snag to hold onto while you got the rescue
together.