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