For example,

 

Foghorn sounds 
 
 
 

Bosun's Pipe Sounds
 
(caution: audio is very high-pitched)


Tip: Try playing all sounds at once.
 
"Race Rocks Lighthouse Foghorn" courtesy of RaceRocks.com
"Onboard" (playing) courtesy of Ben Bray
"All hands" and "Side-Boys" courtesy of The Goat Locker