đ Key Concepts
⢠Basic ship motions: roll, pitch, yaw, heave, sway, surge
⢠Definition of a shipâs axes: longitudinal, transverse, and vertical
⢠Which motion looks like a ship rocking side to side vs nodding bow-to-stern
đ Think About
⢠Picture a ship viewed from ahead or astern: when it rolls side to side, what line through the hull is it rotating around?
⢠Compare roll to pitch: pitch is bow up and downâwhat axis does that use, and how is roll different?
⢠Think of how a pencil lying on a table can rotate: along its length, across its width, or around a vertical lineâ which is most like rolling of a ship?
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Before You Answer
⢠Be clear on the difference between longitudinal axis (bow to stern) and transverse axis (side to side)
⢠Remember: roll = side-to-side rocking, pitch = bow up/down, yaw = turning left/right
⢠Eliminate any option that describes a line that does NOT match the real rotation when the ship rolls in waves