Definition of "leeboard"

[…] on the port side a sofa bed was put up and fitted with a leeboard. On the starboard side a short seat with a folding cot above, which folded […]

1909, Thomas Fleming Day, The Rudder, page 24

Forward of the mizzenmast was an iron box in which the mainsheets worked, and to port and starboard were the leeboard winches, hand-worked.

2014, Tristan Jones, A Steady Trade: A Boyhood at Sea, Open Road Media

I lowered the starboard leeboard. I sent Kester up forward with the binoculars. 'Any buoy,' I told him, 'just yell and point.'

2015, Tom Cunliffe, In the Wake of Heroes: Sailing's Greatest Stories Introduced by Tom Cunliffe, Bloomsbury Publishing

Even in complete reversals from starboard to leeboard in a high sea, no shocks, either electrical or mechanical, could be observed.

1896, Albert Scheible, “The Need of Uniform Voltage”, in The Electrical Trade, page 5

[…] because the leeboard side could be easily unrigged to avoid damaging the rigging, while the starboard side would be required to safely navigate the vessel.

2004, Gayle C Avery, Andrew Bell, Martin Hilb, Anne E. Witte, Understanding Leadership: Paradigms and Cases, SAGE, page 212

Riek's berth was on the starboard side with two women, and mine was on the leeboard side with two men. One of the two men was a baron, […]

2010, George Sjouke Riemersma, 'Sa Wie It' , page 85