Biscuit of Explorers, Having Long-Life Properties
Puzzle 10 of Great Explorations Hard Pack
Question is: Biscuit of Explorers, Having Long-Life Properties
and the answer is: HARDTACK
Word Meaning:
HARDTACK — (nautical) A large, hard biscuit made from unleavened flour and water; formerly used as a long-term staple food aboard ships.
Definitions from Wiktionary.