Here is the full list of all 26 Overboard! achievements.
Talk someone down
Five down
Discuss literature with the highest authority
Four down
Steer the ship
Establish relations with an officer
Clean someone out at cards
Get your way the hard way
Reunite with Malcolm
Get off in 5 hours or less
Get off in 3 hours or less
Three down
Earn a small fortune for your efforts
Two down
Get the killer sent to prison
Allow the killer to escape from justice!
Get yourself a nice man
Put an old lady to sleep
Money, man and murderer in 5 hours or less
Everything ship-shape and Bristol fashion
Everything ship-shape in 5 hours or less
Money, man and murderer in 2 hours or less
Six down
Seven down
Everything ship-shape in 4 hours or less
All of Malcolm's possessions, into the sea