Final answer:
In the context of night diving, when a buddy makes a big circle with their light, it usually signifies 'attention' or 'I'm okay'. This is a standard non-verbal communication signal used by divers.
Step-by-step explanation:
On a night dive, if your buddy makes a big circle with their light, it generally means 'attention' or 'I'm okay'. This common hand signal using a dive light is crucial for communicating underwater, especially during a night dive where visibility is limited. It is a part of standard dive signals that divers should learn and understand before participating in such dives. The circling of light serves as a non-verbal signal across a distance when direct communication is not possible.