What safety equipment should divers always have available?

The correct selection emphasizes the necessity of a comprehensive safety approach while diving. A surface signaling device is vital for alerting surface support or boats in case of emergencies; it ensures that divers can communicate their location effectively. A dive knife is important not just for potential entanglement situations but also for general utility purposes underwater. Lastly, a first aid kit is crucial for treatment of minor injuries that could occur during a dive, promoting quick and effective response in case of mishaps or accidents.

Each of these items plays a specific role in enhancing safety, making their collective presence essential when diving. By having all three, divers are better equipped to handle various scenarios that can arise during dives, contributing to overall safety and preparedness.