The movie is really cool. It has a lot of humor and action. There is a lot of humor around romances. The new lifeguard Matt Brody only sees the lifeguard job as a job where you only need to be able to swim fast for. This leads to dangerous situations.
Mitch feels or actually knows that there is someting very wrong around his beaches. Occasionally he finds drugs on the beach, when people start to die, he starts to investigate what's going on with his team.
I do not want to tell too much about the movie. I do not want to spoil the fun by telling the full story.
It is a good movie! Is it necessary that you have seen the series? No, I do not think so. It is just kind of cool when you know the actors from the series, as a couple of main actors from the series also appear in the movie. Besides that is just a funny and exciting movie.
I wish you lots of fun!