People who clean floors or decks with a swab, which is a mop or a brush.
Swabbers are usually hardworking and keep things clean and tidy.
Examples:
The swabbers clean the ship's deck every morning.
The swabbers use a big mop to clean the floor.
I saw the swabbers working hard to make the floor shiny.
The swabbers make the floor so clean that you can eat off it.
The swabbers are the heroes of the ship, keeping everything spotless.
The swabbers sing while they work, making the deck look like new.