What identifying feature do safe water marks have?

Safe water marks, also known as special marks, are designed to indicate waters where vessels can navigate safely without danger and to signify the presence of navigable channels. One distinguishing feature of safe water marks is that they are characterized by vertical stripes. These vertical stripes, typically red and white, set them apart from other types of markers used in navigation.

The design is not only a visual cue but also serves a functional purpose, helping mariners quickly identify safe waters in potentially congested or hazardous areas. The vertical stripes contribute to the distinctive appearance of the safe water marks, making it easier for boat operators to recognize them from a distance, which is crucial for maintaining safe navigation.

Other options might refer to different types of navigational markers, each with their own specific designs and purposes. Red stripes or horizontal stripes usually denote other marker types, and a lack of stripes would not align with the definition of a safe water mark, which is meant to be clearly identifiable for safe navigation.