What best describes a safe water mark that is painted and lighted?

The best description of a safe water mark that is both painted and lighted is indeed characterized as having a red and white striped design accompanied by a Morse A light. Safe water marks are used to indicate that there is navigable water on all sides and are primarily intended for guiding vessels safely through a channel or towards safe harbor.

The distinctive red and white stripes on the buoy provide high visibility, making it easy for mariners to identify the mark from a distance, while the Morse A light, which flashes in a specific pattern (dot-dash), serves as an additional navigational aid during nighttime or reduced visibility conditions. This combination ensures that the mark is easily identifiable and helps in maintaining safe passage in potentially hazardous waters.

The other options describe elements that do not align with the traditional and established characteristics of safe water marks. For instance, a lighted buoy with a red spherical top mark is typically more associated with special marks or isolated danger marks rather than safe water marks, while flashing red lights are indicative of danger rather than safe navigation. Lastly, a yellow and blue striped buoy does not conform to the standard color scheme used for safe water markers.