Related Clues:

• Baltic and Aegean
• Weight measures for whales
• Pirates' domains
• Map expanses
• 'Seven' things for a pirate
• Blue sections of maps
• Poseidon's domains
• "High" waters
• Major bodies of water
• Watery septet
• Homes for 34-Downs
• A lot, loads
• They're smaller than oceans
• Poseidon rules them
• Caspian and Coral