Related Clues:

• Kind of horse or cow
• Briny expanse
• Ionian, e.g.
• Rivers' destination
• Atlantis cover, supposedly
• Crossing medium
• It has arms and waves
• Reef setting
• Mariner's milieu
• Most of the Earth's surface
• See 38-Down
• Horse or dog lead-in
• Ross, e.g.
• Breeze source
• Great expanse