What indicates that a dive is beginning to come to an end?

When a dive is nearing its conclusion, checking the remaining air supply and the time spent underwater serves as a critical indicator of safety and proper planning. Ensuring that there is enough air left is vital for a safe ascent; divers need to have enough air to comfortably ascend and perform any necessary safety stops. Additionally, monitoring how long the diver has been underwater helps ensure adherence to no-decompression limits and prevents potential risks associated with extended dives.

Other aspects, such as assessing water temperature or searching for marine life, may provide insights into the overall dive experience but are not direct indicators that a dive should be ending. Monitoring the depth gauge is important for safety while underwater, yet it doesn't signify the conclusion of a dive like the assessment of air supply and time does.