Sea Slug

Talk to Holgart with swamp paste who is near Caroline.

Talk to him again and take the fixed boat to the fishing platform.

Climb up the ladder to the north.

Head west and go inside the building via the door on the eastern wall (do not kick the badly repaired wall).

Talk to Kennith (you can talk to him from the other side of the crates).

Go back down the ladder and head to the south-east corner of the platform.

Talk to Holgart to leave the platform.

Talk to Kent on the Island.

Wait for Kent to talk to you one more time.

Talk to Holgart to return to the platform.

Head west and talk to Bailey for an unlit torch.

Pick up the broken glass.

Head to the north-east corner of the platform and take some damp sticks.

Use the broken glass on the damp sticks.

Use the sticks' rub-together option to light the torch (may take multiple attempts).

Climb up the ladder and go talk to Kennith.

Go outside and kick the 'badly repaired wall' north of the door and east of Kennith.

Go back inside and talk to Kennith.

Rotate the crane.

Go down the ladder and talk to Holgart.

Talk to Caroline.

Quest complete!