Thanks for the comments - the seat height thing was a 'not marking the height before I took the post oout' faf, when I put the bike in it's box. I know, I know, it's basics, but the best guess felt a bit too low as soon as I sat on it, but not 'wrong'.
The swimming always seems to come back quickly, and I am aware that I need to work on endurance now if I want to get out the water on the day with anything left in the tank!

Forecast this week is fantastic, Spring has arrived in style and hopefully I will be able to get some quality sessions in.

Happy training!