Had another half hour tonight, which stretched into 40+ minutes. I could tell when I swam yesterday and Monday morning that something has clicked for me - I'm getting the hang of the rotation and rear arm extension now, consistently, and when I did my warm up of two widths of the diving pool, the coach was really impressed by how much better I was.
Then she gave me new stuff to work on and it all went to hell.
It was fun in the diving pool tonight because there was diving coaching going on, and some of the divers were trying very difficult stuff, so the coach used a switch to make a giant plume of bubbles erupt in the middle of the pool, to break up the water surface a bit and give them a softer landing if they mucked it up. So it was like swimming through a giant jacuzzi.
The wash did tend to throw me against the side of the pool though.
Also awesome was the diving coach saying to my swimming coach "Why is she having swimming lessons? She's a lovely swimmer."
Less awesome was me walking home, getting in and realising I'd walked home with my blue plastic shoe covers on.