I’d say which stroke you should use depends on the given conditions. If its flat it doesn’t make much difference but if its sloppy, choppy or gnarly, it does. Paying attention to the waves and timing your breathing accordingly is important. For me freestyle (or crawl as I learned it) is the preferred stroke mainly because its efficient, I like it and I’m good at it.

If I’m swimming from the beach out to the line up, ie against the direction of the waves, no matter what the conditions are, its freestyle because you can smoothly dive a wave. If I’m swimming in to the beach I usually use breast because wave direction is at your back and if a wave breaks over your head its no big deal. If I’m swimming parallel to the beach, outside of the impact zone, its whatever I feel like.

Some years back I snapped my leash on a big NE swell in like late March on an ugly wipeout. It was breaking a good ways off the beach that day so I was a long way out. The first thought through my head was, sheeeeeet how long is it going to take me to get in, because I had been out for a while and was starting to lose body temp. So I started swimming freestyle and I quickly found that the amount of rubber I had on was very inhibiting to that stroke. At that point I’ll admit to being a bit scared. I then turned to a vigorous side stroke which was much easier to do. After a while I realized that vigorous wasn’t necessary because the push of the fetch was moving me along a lot faster than I thought.

Anybody that wants to play in water over their head should be able to swim and IMO every surfer should be able to swim a good 100 yds in any conditions they are willing to surf in.

Just for a laugh try paddling your board butterfly, its interesting.