OK, now that I'm in my place, I'll bore you with some trivia that cdavis didn't mention.
I got my first scuba tank in 1954, and while DCS was well understood in scuba diving, it was thought to be impossible for a freediver to suffer from it. As far as anyone knew, you had to breath compressed air. A retired Navy Master Diver named E.R. Cross used to write a diving tech column in Skin Diver Magazine, and in 1962 he described a problem encountered by pearl divers in Tuamotu and other South Pacific islands. It was called Travana, and the symptoms were what we now recognize as DCS, including crippling in some cases. It looked like the bends, but it couldn't be since they were not breathing compressed air. But Cross had one of what I think was the earliest dive computers made by Scubapro, and he decided to do some simple tests. He just lowered the thing over the side on a string to duplicate the dive depths, times, and surface intervals that he had observed in the pearl divers, and sure enough the computer got bent. Or to be more precise, it said it needed decompression stops. So as I recall (and my memory is not razor sharp after all these years) this was the first time that it was known that freedivers could actually get DCS.
I'm a bit out of my league here but I don't think its a problem for pure competitive freedivers since they are not doing repetitive dives. Please correct me if I'm wrong cdavis or anyone else who knows better. But highly competitive champion spearfishermen have indeed suffered DCS in competitions.
There are a lot of things I worry about while spearfishing, including the fact that a woman got her hamstring removed by a great white shark last week near one of my favorite kelp beds, but I'm afraid that DCS is not one of them.
Edit- after mentioning it, it occurred to me that someone might like to hear about the shark.
https://forums.deeperblue.com/threads/southern-california-shark-attack.108799/