no-wind heading

例句：

1. 1.The ship's no-wind heading is 20 degrees to the north.
   这艘船的无风向度是向北偏20度。
2. 2.The navigational chart shows the ship's no-wind heading.
   航海图显示了这艘船的无风向度。
3. 3.The wind was blowing from the south, so the ship's no-wind heading was correct.
   风从南面吹来，所以这艘船的无风向度是正确的。