Adverb
belowdecks (not comparable)
(nautical) Below the main deck of a ship.
Several months later, as his countrymen jostled past him and went belowdecks, Fong See gripped the railing of the riverboat that slowly glided from San Francisco Bay up the yellowish river toward Sacramento. Source: Internet
Meanwhile our absolutely hapless Dr. Maturin is belowdecks cracking his head into a low beam so hard he sees stars and then valiantly pretending he’s not dazed when Jack bounds down to happily offer him eggs and bacon and coffee. Source: Internet
“You must be wise indeed to stay out here while our countrymen go belowdecks to possible death. Source: Internet