Hugh Manatee
Veteran
People who don't so much swim as drift who nevertheless opt to go in the medium lane.
Lifeguards who let them do it.
Ooh, yes. I have returned to swimming as a sort of self-physio for a shoulder problem. There are some people in the lane who are just so slow. I can't go that slow and not sink.
People who sign off every single reply with their name or something similar.