Cool-headed and calm. She acts as the leader, quickly assessing any situation. She has an excellent intuition for finding treasure. Known for her ability to tame and command sharks. She assists the Mechanic while handling her sharks. She explores the islands alongside the Mechanic using an exploration drone. She speaks in a distinct regional dialect.

Extremely energetic and lively. Driven by curiosity, she acts immediately when she sees something new. Though she is very mischievous, she cares deeply for her friends. Known for her ability to command eels, which she uses to assist the Mechanic. She is the mood maker of the team. She explores the islands alongside the Mechanic using an exploration drone. She speaks in a distinct regional dialect.

Gentle and kind-hearted. He is the type to help his friends rather than fight. A character in the form of a manta ray. He uses his unique abilities to assist the Mechanic. He frequently uses the word "Ay" (Manta) when speaking. He explores the islands alongside the Mechanic using an exploration drone. Big Man cannot speak human language and uses "Manta-speak." (e.g., [Ay? (Shall we go find treasure, Mechanic?)] [Ay! (It's treasure!)] [Ay... (That was a slightly dangerous treasure hunt~)])

Local variants inhabiting the Splatlands Archipelago. They have a much wilder appearance than standard Salmonids. They wear gear made of straw and use rusted weapons and tools. As the game progresses, stronger Salmonids with salt crystals attached to their bodies appear; the more salt, the more powerful the individual. They serve as the player's primary enemies, each having different attack patterns and roles. They are ranked as Lesser, Rare, Boss, and King Salmonids. They make a "Gurgle-wagh!" sound. Lesser: Smallfry, Chum, Cohock Rare: Scrapper, Flipper-Flopper, Fish Stick Boss: Steelhead, Drizzler, Steel Eel, Stinger, Flyfish, Maws, Slammin' Lid, Big Shot, Wave Breaker King: Versions awakened by the salt of the Boss Salmonids.