TYPICAL boats have outboard motors. Look at the back end of the boat when it turns right. The outboard motors swing right, the propellers push water to the right, and the boat turns right. The propeller is under the boat pushing all of the propeller force towards the right. This tries to make the bottom of the boat move towards the left - so looking at the back of the boat this forces it to rotate clockwise - “into” the turn. TYPICAL ship propellers always push straight out the back. The rudders then push a portion - only a portion - of the propeller force to one side. This force does try to rotate the ship into the turn but it’s much less than full propeller force, and the weight of the centrifugal acceleration of the superstructure of the ship is larger and causes it to roll “out of” the turn.

TYPICAL boats have outboard motors. Look at the back end of the boat when it turns right. The outboard motors swing right, the propellers push water to the right, and the boat turns right. The propeller is under the boat pushing all of the propeller force towards the right. This tries to make the bottom of the boat move towards the left - so looking at the back of the boat this forces it to rotate clockwise - “into” the turn. TYPICAL ship propellers always push straight out the back. The rudders then push a portion - only a portion - of the propeller force to one side. This force does try to rotate the ship into the turn but it’s much less than full propeller force, and the centrifugal acceleration of the superstructure of the ship is larger and causes it to roll “out of” the turn.