Fish-Man Island New World mein enter karne se pehle samundar ki gehrai mein 10,000 meter neeche hai. Ye island fish-men aur mermaids ka ghar hai aur ise coating wali ship ke zariye visit kiya ja sakta hai. Fish-Man Island ka ek gehra aur dark history hai — fish-men aur humans ke beech taareekhi dushmani. Queen Otohime ne dono species ke beech peace ke liye kaam kiya tha. Yahan ka new Fish-Man villain Hody Jones tha jo bina kisi wajah ke humans se nafrat karta tha — ye ek psychological angle tha jo Oda ne brilliant tareeke se dikhaya. Fish-Man Island arc mein Luffy ne Hody Jones ko haraya, Shirahoshi (mermaid princess) ke baare mein pata chala ke woh ancient weapon Poseidon hai (Sea Kings ko control kar sakti hai), aur Big Mom ke saath Luffy ki pehli takkar hui. Luffy ne Big Mom ko challenge karte hue kaha ke woh Fish-Man Island ko apna territory bana raha hai. Fish-Man Island par hi "Joy Boy" ka ek aur Poneglyph mila jo ancient kingdom ke raaz rakhta hai. Ye arc Straw Hats ke New World mein enter karne ka gateway tha aur definitely One Piece ke endgame ki taraf ek bara clue tha.