One of the two Fenders on my boat, a Polyform HTM2,
started getting the slimy sticky surface disintegration,
and finally split open at the hole where the line is
threaded through the fender.

I had read that Polyform offers a limited lifetime
warranty. With "Polyform's limited lifetime warranty,
these fenders are guaranteed for life!"

Polyform didn't even bother to reply to my email.
Looking up the warranty on Polyform web site showed
why, the warranty is a total scam: It excludes not
only the obvious stab with a knife, etc., but also
transfer of ownership, exposure to chemicals that
degrade or discolor plastics, and:
UNUSUAL CONDITIONS SUCH AS, ..., hurricenes,
UV LIGHT BREAKDOWN, OR ULTRAVIOLET RAYS.

Leave them out in the sun, and the lifetime warranty
is void. A FENDER! Do you store yours inside????

The funny thing is that the other fender (some no name)
that was next to the Polyform didn't degrade at all,
although it didn't look newer.

Lesson learned: Stay away form Polyform, the fender
didn't seem to hold up better than the no name next to
it, and the warranty is a total scam.

Unusual Conditions such as hurricanes or sunshine.
Duh.