Just when I was thinking I was on a bit of a plateau with swimming, along came today.
1000 m 18:48
This is the fastest I've done 1000 m since some time in my late 20's. My heart rate at the end was 144 which is also the highest it's been after a swim in a long time, but I didn't think I was actually working that hard. My stroke felt strong and smooth, and it wasn't until half way through I realized I was on track for a fast time.
100 m times were: 1:42, 1:50, 1:53, 1:55, 1:56 (500 m 9:18) 1:56, 1:54, 1:55, 1:54, 1:49.