I really enjoy swimming in the ocean
Swimming is among the top public recreational activities.  I hope you swim where there is a lifeguard!
I try too, one time I saw a shark while swimming
Be careful.  Although lifeguards are rescuers, they can't protect you from sharks.
what is the best protection from sharks?
Shark attack prevention
There are a range of shark attack prevention techniques employed to reduce the risk of shark attack and keep people safe. They include removing sharks by various fishing methods, separating people and sharks, as well as observation, education and various technology-based solutions.
Techniques that involve culling sharks are contentious. Environmental groups have voiced concern over the impact of reduced shark numbers on ocean ecosystems and the problem of by-catch of other marine life, particularly endangered species. Because sharks are important to the ecosystem
Lifeguard tower
Lifeguard towers are used at recreational beaches or public swimming pools to watch and supervise swimmers in order to prevent drownings and other dangers. Lifeguards scan for trouble from the structures, which vary from beach bungalows by the ocean to poolside towers. Lifeguard towers are also used to spot sharks and other threats.
The towers have featured in television shows including "Baywatch". Their construction is sometimes paid for with fundraisers, and their operation and staffing is subject to funding availability. Design contests have challenged architects to offer