What does the buddy system entail in the context of night diving?

The buddy system in the context of night diving fundamentally involves maintaining regular checks and ensuring close proximity between divers. This practice is exceptionally important during night dives or in limited visibility situations because it enhances safety and allows for immediate assistance if needed. Close proximity ensures that divers can easily communicate and respond to each other's needs, which is crucial when visibility is compromised by darkness. Regular checks reinforce this connection, enabling divers to confirm each other's well-being and readiness throughout the dive.

The other options do not align with the principles of the buddy system. Using separate locations to explore could lead to isolation and increased risk, diving without a partner completely negates the concept of a buddy system by eliminating any support structure, and relying solely on hand signals could limit communication and awareness in a dark environment where visibility is already reduced. Thus, the importance of checks and proximity underlines the correct understanding of how the buddy system operates in night diving scenarios.