Which of the following items is essential safety equipment on the pool deck?

A first aid kit is essential safety equipment on the pool deck because it provides the necessary supplies to respond to injuries or emergencies immediately. This includes items such as bandages, antiseptics, and other medical supplies that can help treat minor injuries on-site before professional medical assistance arrives.

In a pool environment, incidents can happen quickly, and having a first aid kit readily available ensures that lifeguards and staff can act swiftly to manage injuries like cuts, sprains, or other emergencies, thus enhancing the safety of the pool area.

While swim toys, mobile phones, and lifeguard whistles are important for various aspects of pool operation, they do not serve the same critical function as a first aid kit. Swim toys are recreational and do not contribute to safety, mobile phones are important for communication but are not a direct safety aid, and while lifeguard whistles are vital for signaling and communication among lifeguards, they do not provide immediate medical care. The presence of a first aid kit is a fundamental aspect of ensuring the health and safety of patrons at aquatic facilities.