I recently bought an underwater video camera, and have recorded my first videos.
Here is a clip of my butterfly. (It's my worst stroke, but I'm a sucker for doing things in IM order. Plus fly videos seem to be the hot topic at the moment.)
YouTube- Butterfly 10-02-19
I knew that video would be great feedback: the few times I have seen an above-water clip of myself, I have been astonished to see things I was unaware that I was doing. But underwater video is even better.
Flaws I can see:
hands move too close in front?
too much glide/pause in front?
stroke not flat enough: too vertical during recovery
first kick (with hands extended) is too late?
first kick (with hands extended) is too hinged at the knee
I'm uncertain about my own diagnosis, though, and would welcome other opinions.
Also, since my timing & stroke actually feel fairly smooth to me while swimming (very different from how it looks), I'd love to hear about drills or key attention points that can help me focus on the changes I need to make.