"Do you still have any Hard-Life Fish today?"
The customer's query pulled Boss Zeppy Fish back from his brief reverie to reality.
He turned his head and saw a figure that resembled... an orange cat, a fat orange cat with an ammonite helmet on its head, clutching a double-headed harpoon.
"There's one fish left, God of the Deep Sea. You've come quite late today,"
Indeed, this fattened feline was the sea deity of this world. The fishmen called it the "Blind Fish-eating God."
Long ago, the fishmen had understood the true nature of their world.
The surface ocean operates as the normal part of the world, including the seabed, but once you venture into the deep sea, you encounter subspace phantoms.
For mortals, these entities pose a significant danger, but to some lifeforms with characteristics similar to those of subspace, the area isn't a hazard zone.