Swimming in MD

Yesterday, was my first swim in about 2 weeks and it felt like it:) I joined the local tennis club where they have a fitness room and indoor pool. The pool is nice but only 3 lanes were open in the morning so we were doubled up. I felt out of shape so only swam 16x50s intervals. It wasn't until after my swim that I realized lengths are 25 meters. I'm used to swimming yards and 50m is about 54 yards - makes a difference. 16x50s is about 1/2 mile. I started with a 1:30 practice split but soon reverted to my old 1:55; now I know why and don't feel like a slug:) Hope to hit the pool again around lunch time; hopefully, less people.