“Have you ever smelled submarine fuel, adventurer? 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.”