I returned to the squidshark lair to get the last SeaTruck fragment and some lithium. I’ve found that the best way to survive encounters with the squidshark is to avoid encountering the squidshark. I cling to sides of the cave and climb through holes, staying out of sight until I locate the camera I set as a marker to the fragment or lithium.
I nearly died again. This time, a leviathan called a chelicerate mauled my SeaTruck. I foolishly thought that I could play dead by shutting off my lights, but the monster came back and mauled me some more. Learning my lesson, I hightailed it out of there back to the safety of my seabase. I can’t attempt exploring the Purple Vents until I get some decoy missiles or some other defense.
I have to start being more cautious in general. One day I might leave the base and never return.