What characterizes a repetitive dive?

A repetitive dive is defined as any dive that occurs after a previous dive on the same day. This is significant because after making a dive, the body starts to absorb nitrogen from the surrounding water, and subsequent dives can increase the risk of decompression sickness if not properly managed.

In the context of diving physiology, each time a diver descends after having already dived that day, the nitrogen loading in the body increases as a result of the second dive. This necessitates careful monitoring of time limits and depth to ensure safe diving practices.

The other options describe scenarios that do not necessarily relate to the concept of repetitive diving. Diving deeper or longer than a previous dive describes specific conditions of the dives rather than their sequence. A dive with a different buddy does not influence whether a dive is repetitive or not, as it is the timing and sequence of dives on the same day that are crucial in this context.