Subnautica: Silicon rubber - how to craft? Subnautica Guide and Walkthrough

Silicon rubber is one of the basic crafting materials. It is used to craft items like Fins, and requires Creepvine Seed Cluster, which is common near your capsule. These are the glowing pods in the middle part of the stem.

After you have collected them, return to your capsule and use the Fabricator to craft silicon rubber.