Possible Clues:

• Sailor's back on ship pursuing ocean fish
• Fish related to the grouper
• Swimmer with the deep deep voice
• Deep, deep fish
• Fish in deep taken by aquatic mammal, mostly
• Chilean catch
• Grouper, e.g
• Fish often pan-fried
• Lord Coe entertaining a fool to fish
• Fish dish that might be 'dropped' in the ocean (GET IT? GET IT?)