There's been many studies showing that wetsuits give a speed advantage on average around 6% (this is on average). My understanding is it's because of the buoyan

There's been many studies showing that wetsuits give a speed advantage on average around 6% (this is on average). My understanding is it's because of the buoyancy. There's an idea that they're less necessary for really skilled elite swimmers but that's controversial. Having worn them I can say there is definitely constriction around the arms even with good-fitting wetsuits (relative to no wetsuit material), so I understand the idea that if you're good enough the wetsuit would just get in the way (not saying I'm that good, just that the idea is consistent with my experience). However, I've also read pretty convincing arguments that if you take any swimmer and put them in a wetsuit that fits them well, on average across swimmers, they'll swim faster. Regardless, in a typical triathlon or meet, there is usually an observed speed increase of a slight amount, which ostensibly puts someone at a speed disadvantage.