Noun
deep blue sea (countable and uncountable, plural deep blue seas)
Sea, ocean, open sea.
Coleman 2005, p. 271. In 1955 Leigh starred in Anatole Litvak 's film The Deep Blue Sea ; co-star Kenneth More felt he had poor chemistry with Leigh during the filming. Source: Internet
This reminds me of that bit in the movie Deep Blue Sea where ‘Preacher’ (LL Cool J) thinks he’s going to die, and his last words to the world are how to make the perfect omelette. Source: Internet