Went swimming today and it was one of the set ups where they have slow/medium/fast lanes, and you pick the lane you swim in based on the people already swimming in them, not your own ideas of speed (eg you might think you're extremely fast, but if the fast line is full of Olympians, you'd pick a different lane). There are signs up specifically telling you to pick your lane in this way.
I was swimming in the fast lane with two other people -we were clearly faster than people in the other lanes, so it was the right place to be. Another man came and got in the pool twenty minutes after I got in, and he was swimming much faster than any of us were going - which obviously means he kept running up the back of other swimmers! Every time I knew he was directly behind me I'd pause at the end and let him overtake me for the next one, but he kept huffing and rolling his eyes. He then started overtaking all three of us during lengths - which is fine in principle, just not if it means the person coming the other way had to stop and wait and the person he was overtaking got nearly kicked in the face each time.
AIBU to think this is really inconsiderate/rude? There was just so much tutting and eye rolling at the audacity we had to be swimming faster than people in other lanes, yet not swimming as fast as this man clearly wanted to. Minor issue in the grand scheme of things but it really annoyed me - as well as actually being quite dangerous RE being kicked in the face/kicking him in the face - and made my swim a lot less enjoyable 
Surely if you want to swim faster than everyone else you time it right and wait for everyone else to be on the length back before you start, or something, not just passive aggressively showing your displeasure at other swimmers?