There's a distinct lack of renewable light sources in Shipwrecked. In Reign of Giants, or even the base game, lanterns and the miner's hat can be refueled with light bulbs, which are abundant in the caves, and can be gathered without much trouble from day 1.
It seems there's no such thing for Shipwrecked, with Bioluminesce being limited. Tar lamp is unreliable, just like the torch.
Fireflies from the slot machine with a 2% chance are not reliable. For your boat, you could rely on Yaarctopus, but a big part of the game still happens on land, where regular means of light are needed.
I'm wondering what's the design idea for this lack of renewability in light fuels. Is it because the developers expect people to use the Seaworthy to go back to caves to craft several lanterns?
I actually went on and made changes to the prefabs that deal with bioluminesce and its spawner to make it renewable, but perishable. I'm currently testing the changes, might publish it as a mod soon.
I browsed previous discussions on this, and most folks seem to agree, as seen on:
" Renewable biolum! No reason why this resource shouldnt respawn every night in new locations indefinitely. "
" There's no reason biolum shouldn't respawn. There's an finite amount of bottle fuel unless you want to farm the slot machine for fireflies which isn't worth. "