The Azure Sky, the Heavens
Puzzle 18 of Deep Sea Journey Hard Pack
Question is: The Azure Sky, the Heavens
and the answer is: FIRMAMENT
Word Meaning:
FIRMAMENT — (usually uncountable, literary, poetic, also figuratively) The vault of the heavens, where the clouds, sun, moon, and stars can be seen; the heavens, the sky.
Definitions from Wiktionary.