This was shot using a 500mm mirror lens, so will be quite different than a refractor in terms of smooth bokeh etc.
Even so, it is possible to get some interesting shots. It would help if I could anticipate the surfers better as you need to focus on a
small bunch - using Focus Peaking on the rear LCD - and hope that's where the next good wave will come.

NB: Shot with Monopod at beach level for stability. Mirror lenses are very small and lightweight compared to traditional refractors,
so unless you're a photography pro with Canon 'L' glass, such a lens is more likely to get taken along and actually get some use.

In good sunlight they can produce interesting images and I'm sure a skilled surfer
would know exactly what to be looking for in terms of shooting the most decisive action.

If you have a Sony DSLR then there is a 500mm autofocus mirror lens that will fit.
You can get them either as the original Minolta or Sony on EBay from around £400 used to £800 new.