Which type of hazards should divers be aware of underwater?

Divers should be particularly aware of marine life, entanglements, and sharp objects because these specific hazards can pose significant risks during a dive. Marine life, while often fascinating, includes species that can be venomous or aggressive if provoked, such as certain types of jellyfish, urchins, and even larger predators. Understanding these species and maintaining a respectful distance is crucial for safety.

Entanglements are a key concern as divers may become trapped in fishing lines, nets, or underwater debris, which can hinder their ability to surface or move freely. Divers need to be trained in how to avoid these situations and have the skills to manage them if they occur.

Sharp objects, such as broken glass or jagged coral, represent a physical risk to skin and equipment. Being aware of one's surroundings and the potential presence of these dangers can help prevent injury.

While high currents and extreme temperatures can affect dive conditions, and while sound pollution and visibility issues can impact the experience, they do not pose the direct, immediate physical risks that the hazards listed in the correct answer do. Other divers and their equipment are important to keep in mind for awareness and courtesy, but they also do not pose the same inherent dangers that require proactive avoidance and management by divers.