[Timmah]

Depends on your swimming ability. You can easily drown if you panic when large waves land on you and force water into your mouth/nose. or if you get swept out by a rip current and don't swim sideways and keep your cool.

Don't try it without a lifeguard nearby until you're experienced. Be confident momentarily being held underwater against your will. Never take your eyes off the ocean, because not all waves are equal in size or period. Personally I found that swimming out past the waves is the most difficult/frustrating (you need to be past them slightly in order to catch them).

Not all beaches are created equal. Some have exposed rocks, huge waves that can lift you and smash you directly into the sand (YouTube "the wedge, Newport beach" to see what I mean), or deadly currents. So research before you go.