Centreboard
/ˈsentərbɔːrd/
Definition 1 of 1
Pro Tip 1/3Sailing Essential
Centreboard is crucial for controlling a sailboat's balance and direction, especially for small vessels. 
Without the centreboard, the small sailboat struggled against the wind.
Pro Tip 2/3Adjustable Stability
The centreboard can be adjusted to optimize sailing performance in different water conditions. 
They lowered the centreboard further to stabilize the boat in the choppy sea.
Pro Tip 3/3Nautical Jargon
Centreboard is specific to sailing and boating, so use it in contexts familiar to these topics. 
During the race, I heard the captain shout to lower the centreboard for a tighter turn.