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