Have you ever smelled submarine fuel, <name>? It's nasty stuff. Unfortunately, we need to burn huge amounts of it to get the Verne to move, and it's both bad-smelling AND deadly to the local wildlife. We need to be more environmentally conscious.
The sea creatures nearby have particularly oily flesh. Take this device up to Seabrush - just above this cave - and use it on the corpses of terrapins, remoras, and hammerhead sharks. Their oil might save the lives of hundreds of other sea creatures.
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Please... don't tell the other goblins that I'm an environmentalist! I don't think I can take the mocking!
Completion
<Fiasco sticks a finger into each sample and sniffs it.>
Exit the cave, then turn around to the northwest (left). On the "seafloor" of the ridge are terrapin and hammerheads, while hanging out underneath overhangs are remora. Also keep an eye out for Alliance Sea-Scouts. Killing one starts Secure Seabrush automatically.