This stuff is plastic, & waterproof. Never tried it, but it could probably take YEARS immersed in water. It might be covered with algae, but still useable.
The green stuff sounds like some kind of epoxy or polymer/epoxy. I've always had trouble mixing it properly.
WARNING & DISCLAIMER:
SELECT AND USE OUTDOORS AND SURVIVAL EQUIPMENT, SUPPLIES AND TECHNIQUES AT YOUR OWN RISK. Information posted
on this forum is not reviewed for accuracy and may not be reliable, use at your own risk. Please
review the full WARNING & DISCLAIMER about information on this
site.