centerboard

1. The movable diversion devices which are put forward in this paper are installed on the centerboard. It has characteristics of safety, convenience, efficiency, shortcut and reuse so that meet the high-mobility require of rush emergency.
   本文提出的活动式导流装置是将导流板安置在活动船上，具有安全、方便、有效、快捷、可重复利用的特点，可以满足抢险的高机动性要求。

noun

1. a retractable fin keel used on sailboats to prevent drifting to leeward

   Synonym:    centreboarddrop keelsliding keel