The phrase "lowest deck" is correct and usable in written English.
You can use it to refer to the lowest level of a structure. For example, "This ship has seven decks, the lowest deck is used for cargo storage."
"There were four Israeli soldiers brought to the lowest deck.
Dominique Ramirez, 18, a college student who was on the lowest deck, survived the crash.
We were on the lowest deck of the ship, so we all rushed out of the room and pressed the emergency button as water rushed in.
The body was placed on a board, tipped up and then "eased into the sea" from the carrier's lowest deck, the official said.
These cabins offer views and fresh air and are much more popular than those on the lowest deck with only a high window just above the waterline, which sell last.
Right above the hold was the orlop, the lowest deck.
The mood of the mess halls and wardrooms, even in the lowest decks, is a kind of grim acquiescence.
Those on the lowest decks, nearest the site of the collision, felt it much more directly.
"Sometimes they will, because let's face it, if you were a ghost, would you rather hang out in an empty house with other ghosts, or with people and have a good time?" Grady and I sat in the low deck chairs, while Chris and Andy fanned out around the gin, depositing small cameras and tape recorders here and there.
Some migrants are pushed into the low deck where they are more susceptible to drowning and suffocation.
A low deck of stratus could indicate a station is still north of a warm front, while thunderstorms can indicate the approach of a squall line or cold front.
