centerboard
/ˈsɛntərˌbɔrd/
noun
- A retractable keel or fin on a sailboat that can be raised or lowered to adjust the boat's stability and direction, especially in shallow water.
- In shallow waters, we raised the centerboard to avoid hitting the bottom.
- The sailor lowered the centerboard to keep the boat from drifting sideways in the wind.
- The old wooden sailboat had a heavy centerboard that required two people to lift.