I work as a lifeguard at the beach.
I know a lifeguard watches out for safety and rescue, did you work at the ocean or a pool
I worked at a pool.
you have to be a strong swimmer to be a lifeguard, you must be able to swim really well
Lifeguard
Lifeguard
A lifeguard is a rescuer who supervises the safety and rescue of swimmers, surfers, and other water sports participants such as in a swimming pool, water park, spa, beach or river. Lifeguards are strong swimmers and trained in CPR/AED first aid, certified in water rescue using a variety of aids and equipment depending on requirements of their particular venue. In some areas, lifeguards are part of the emergency services system to incidents and in some communities,lifeguards may function as the primary EMS provider.
8. Unknown Scenario; students face an unknown scenario in which they will have to successfully rescue at least two casualties from the water. Casualties may be in any condition and safety resources are varied.
9.You can apply for bronze medallion at the age of 12 as long as you have passed the rookie lifeguard course up to gold 3 otherwise you must be 14 
9. Oral Examination; testing knowledge of basic first-aid, diagnosis, water safety etc.
For a description of the Medallion itself see Bronze Medallion