What is the primary purpose of a spherical float in buoyage?

The primary purpose of a spherical float in buoyage is to mark underwater cables and pipelines. Spherical floats are designed to remain on the water's surface, allowing them to indicate locations of submerged infrastructure, such as cables and pipelines, which are critical for safe navigation and operational integrity. By visually marking these areas, they help prevent accidental damage from vessels, fishing activities, or other marine operations.

While options regarding indicating underwater hazards, signaling maritime traffic, and providing reference points for navigation are important functions of different types of navigational aids, they do not align with the specific function of a spherical float. The float specifically serves to draw attention to and clearly mark the position of cables and pipelines to enhance maritime safety and manage the risk of interference with these essential subsea installations.