在主甲板下面
on a level of a ship below the main deck
Our cabin was below decks. 我们的舱位在主甲板之下。
The six men had made the two-week journey in a cramped shipping container below decks.
Visitors are not permitted to go below decks.
People were trapped below decks as water flooded into the ship.
They found four feet of water below decks.
See also: deck noun (FLOOR)