centerboards

/S EH1 N T ER0 B AO0 R D Z/
noun
  1. 1

    The adjustable keel on a small yacht or dinghy that acts, among other things, as ballast and to counteract the sideways force of the wind.

Source: https://en.wiktionary.org/wiki/centerboard, https://en.wiktionary.org/wiki/centerboards, https://en.wiktionary.org/wiki/centreboard