Brian Nystrom wrote:

Even worse, if you rip a gasket, the suit can fill up with water and
cause you to disappear under water, as RBP'er Larry Cable witnessed when
he had to "swim" with a swamped dry suit. The air trapped inside your
leg pants after you rip a neck gasket and the suit floods can also cause
you to float upside down, making it very hard to breathe.

Incidents like that are exceedingly rare. Seals are not fragile
unless they're old and are in need of replacement. They don't just
spontaneously tear for no reason.

Except when the reason is old age!

In the March 23rd 1998 high water on the Illinois river in Oregon,
two people died from taking a "long swim". I know for a fact that
one of them tore his drysuit neck gasket during the trip.

OTOH it is amazing that some people wearing drysuits survived swims
over a mile long. That might not have happened in wetsuits.

Brian or anyone, when ya take good care of gaskets by washing salt
and perspiration off them, and by coating them with 303 Protectant
or equivalent, how do ya know when they are in need of replacement?