This, the 4th map the campaign (by Ditpus) takes place on a ship.
The angle that the boat is resting on gives this map a disorienting feel, and again this looks like another great map in this campaign ...
This just leaves The Lighthouse as the finale.
Extract the files and copy files to: C:\Program Files\Steam\steamapps\common\left 4 dead\left4dead\
Open the Console and type:
Death Aboard III - Docks
Death Aboard II - PrisonYard
Death Aboard I - Prison
Video by Zilla422.