Related Clues:

• Baltic, for one
• Irish, e.g.
• Caspian --
• Sailor's realm
• Last word of 'America the Beautiful'
• Mermaid's realm
• Marmora, for one
• Aegean --
• Horse preceder
• ____Horse
• "Titanic" setting
• "Finding Nemo" setting
• Salt water
• Salty expanse
• It's certainly fishy