Got back into swimming last September when MiniGB started school and I had Friday to myself...
Started off doing 1:1 crawl:breaststroke and slowly moved to 2:1, 3:1, 4:1 and then all crawl.
Sep 2014: 264m, 515m, 666m
Oct 2014: 931m, 980m, 1229m, 1440m
Nov 2014: 1552m, 1465m, 2163m, 1265m, 1176m
Dec 2014: 2600m, 490m, 1532m
Jan 2015: 1199m, 2352m, 490m, 2927m
Feb 2015: (holidays), 1264m
Mar 2015: 2716m, 1665m, 462m, 4137m, 2597m, 1332m
Apr 2015: 5128m, 4578m, 4462m
May 2015: 4841m
(Pool then almost shutdown for refurbishment, I could never go when it was open to everyone and so I stopped).
Luckily I can channel my inner Audaxer when swimming and spend 1h30 in a pool doing endless lengths without getting bored.
Back onto it now after those 4 months off and all stamina has gone:-
Sep 2015: 441m, 686m
After both of those I was utterly knackered (mind you, I did do the first 100m of each swim in ~85s, way too fast as my pacing has gone).
Had swimming coaching for years when I was younger and competed for the county aged 12/13 and luckily the technique seems to have stayed with me. Those big swims (4k+) were done at an average of 115s/100m (just pull, no kicking, all of them done with a pull buoy between my legs). Seem to have the lung capacity for it too as I only need to breathe every 4 strokes (always used to have to breathe every 3 when younger).
Should be back up to 5k swims by Jan, and hopefully 10k a week total volume (5k, 3k faster, 2k of drills)