Which of the following is an example of a natural navigation aid divers use during diving?

Ripples in the sand serve as a natural navigation aid for divers because they indicate the flow of water and the current's effects on the seabed. Observing these ripples can help divers understand the underwater environment, such as which direction the current is flowing and how it may influence their ascent, descent, or overall navigation. Natural features like sand ripples can provide clues about the terrain and formations, assisting divers in orienting themselves underwater without relying on man-made or technological aids.

In contrast, ropes and underwater maps are tools used by divers for navigation but do not qualify as natural aids. Global positioning satellites are advanced tools that are not typically effective underwater due to signal limitations, making them ineffective for navigation while diving.