I did my first post lockdown pool swim today! I did a little bit in the sea over the last few weeks whilst on holiday but nothing too strenuous. It Felt So Good! Only managed 60% of what I was doing in March but I'm getting back. The clear head space was delicious.
Our pool has between 4-6 90 minute slots per day that you have to book in advance. The latest available one is 5:15pm, which will be the only one I can do when I return to work. There were 5 lanes today, 2 slow, 2 fast, 1 medium. I went in the medium as there was only 1 other person, although a third joined us later.
I think the thing about lanes and speed is a little bit like motorways, you have to match your speed to the others already in. So you could be a slow swimmer but if others are much slower, you might be better off in medium. Also check out how many others are in there, there's no point 6 swimmers using a slow lane if there's only one in a medium.
In March, I was about 40-45 seconds per length. So I mainly swim medium, but really try hard to give way to faster swimmers where I can (did so today once). I do find medium can attract faster (usually male) swimmers that would rather be the fastest in a medium lane, than go in the fast lane and be the slowest!
But it really comes down to etiquette, there's no shame in letting someone faster go on, and I prefer swimming when I haven't got someone on my tail. It's the ones who wait until you approach and are almost ready to turn lengths and then they set off that really get my goat, not everyone has a rest after a length!