Throw Mode/Taking off from a moving base

If I wanted to have the aircraft stabilize mid air after being tossed. How should I approach this with ArduCopter? Sometimes the arming may happen on a boat (moving base and metallic) and the aircraft is bound to get compass variance and pre-flight check issues. All I want to do initially is have it stabilize some time after it is launched (e.g. remote switch). Any thoughts?

Thanks!