Related Clues:

• Like bioluminescent fishes
• Opposite of shallow
• From far down
• Adele's 'Rolling in the ___'
• Great Harbour _____ (Newfoundland Ghost town)
• Cavernous
• Hard to understand exercises a journalist rejected
• Strangely, when there's more than one they become high
• Sea bass
• ... low in pitch and away from wicket
• Pacific character of a drug, amphetamine, being reversed
• Low went up
• Profound - cunning - sea - bass
• Profound - sea
• Wise - difficult to understand