"Lloyd Sumpter" wrote in message .. .
Hi,

Whenever I need to work on my prop, etc. underwater, I've just slapped
on the mask and fins and held my breath. But I've always wondered: why not
rig up a hose arrangement to be able to breathe? We're not talking 50-ft
depths here, so I'd think it would be pretty safe. Perhaps some kind of
non-collapsable hose on the end of a snorkel?

Does anyone do this? Why or why not?

Lloyd Sumpter
"Far Cove" Catalina 36

Because if water got into the top end, it would exert a pressure on
your lungs of about .5 psi/ft of depth. So if you are 10' down, it
would exert a pressure of 5 psi above atmospheric pressure.