Minashi of the White Shell A small, barnacle-like aquatic humanoid monster. The area above her nose is covered by a hard, white-gray shell, and she has no visible eyes. Her smooth, grayish-white upper body resembles a woman, but her skin is damp and bloodless, dotted with small barnacles on her shoulders and arms. From the waist down, she is a massive barnacle shell itself, crawling by clinging to the hull or rocks. She climbs from the outside onto the deck, eroding the very ship that the victim thought was a safe zone.

Utsuro of the Ripped Gills An eel-themed monster that infiltrates the ship. She has wet, grayish-white to blackish-green skin with dull yellowish-brown mottled patterns, crawling along floors and walls with long arms, thin fingers, and blackened claws. From a distance, her face looks like a woman's, but her mouth is ripped open nearly to her ears, lined with multiple rows of needle-like teeth. Her lower body is a long, slender eel-like tail, allowing her to slip into drains, under floorboards, between cargo, and into dark corridors. Even if one flees inside the ship, that is Utsuro's hunting ground.

Mizuha of the Sinking Threads A translucent aquatic monster themed after a jellyfish. She has a pale, thin female upper body, with a milky-white and light purple jellyfish-like membrane spreading behind her. Her pupils glow faintly white-blue, and she is expressionless, sometimes appearing like a drifter seeking help. Her lower body consists not of legs, but of countless thin poisonous tentacles spreading beneath the surface. She quietly entangles those who fall into the water, numbing them; the more they struggle, the deeper she wraps around them to pull them down. She is the existence that eliminates the option of escaping into the sea.

Nagiri of the Black Back A large aquatic humanoid monster themed after an orca. From a distance, she appears to have a female upper body, but she is actually a massive monster distorting an orca's predatory nature into a humanoid form. She has a wet black back, cold white belly patterns, a large dorsal fin, small emotionless black eyes, a wide mouth, and thick teeth for crushing. She circles the ship, rams the hull from below, and destroys rudders or means of escape. She is responsible for capsizing and destruction, capable of tilting a small boat just by placing her hands on the gunwale.