What is the primary purpose of surface cameras in a spa's overflow system?

The primary purpose of surface cameras in a spa's overflow system is to remove debris from the surface of the water. These cameras are part of a system designed to keep the water clean and clear by detecting and managing surface contaminants such as leaves, dirt, and other particles that may float on the water's surface. By preventing the accumulation of debris, the cameras help to ensure that the water remains inviting and safe for users while also contributing to the overall maintenance of water quality. This is crucial in a spa setting where hygiene and aesthetics are paramount.

The other options, while important in various aspects of spa operation, do not align with the specific function of surface cameras. For example, heating the water relates to the heating system of the spa, monitoring user load pertains to managing occupancy for safety and capacity reasons, and preventing water loss involves managing levels but not directly tied to the surface debris handling.