The first undersea telegraph lines were insulated with gutta percha. A plastic like plant resin.
When I first started my career we had RG-8 coax cables in our system that were insulated with gutta percha. It is kinda yellowish green waxy stuff that is very similar to HDPE. Many of you also have gutta percha in your mouth. They fill your tooth with it when doing a root canal. I like to think my teeth and undersea telecom cables are related. Gives me warm fuzzys....
