Originally Posted by Talvi
It may help here if I clarify/expand on the difference between what I called swimming in circles and swimming in clockwise/counter-clockwise traffic flows.
In Finland we swim in 2.5m wide lanes each separated from the other by a lane rope. Each of these lanes is then notionaly divided by the swimmers into two 1.2m wide tracks, around the lane marker line on the bottom of the pool, and swimmers swim in a counter-clockwise flow, up one side of each lane and down the other, turning on the wall "T" in close to a normal manner. No swimming across the end of these lanes is needed or possible and this is the key difference to the Scottish "lanes" system.
The offer of "lane swimming" in Scotland is made by removing lane ropes so that lanes become combined. Swimmers are obliged to swim in a circle, clockwise, in these larger areas so it is not possible to turn in a normal manner at the end as there is a 5m+ width to cross before you are able to swim back in the opposite direction. Slow breastroke swimmers manage to keep swimming all around the circular path but freestylers have to either stop and shuffle across the ends before doing another lap, making swimming more than 25m at a time impossible, or else come off the wall at an angle, with the attendant risks of collision etc.
Lanes are combined in Finland too, but only for vesijuoksu (water-running) and other water based exercise, not for lane swimming.
I've never seen what you call "Scottish" lanes. The usual protocol here is that people swim counterclockwise (sort of like a typical U.S. road where motorists stay on the right side of the road, from their point of view).
It's also common, if there are only 2 swimmers in a lane, for each swimmer to stay on one side of the lane (effectively dividing the lane into 2 half-lanes, with each swimmer staying in their own half lane), so that if the swimmers are swimming at different speeds, they don't get in each other's way. At some facilities, this dual protocol is actually posted, but at others, the 2 swimmers just agree to it between them.
The weirdest thing I ever saw was a pool with extremely narrow lanes where it was impossible for 2 swimmers to pass each other in a single lane. So they only allowed 1 swimmer per lane. If all of the lanes were full, you had to write your name on a white board waiting list, and when there was a waiting list, swimmers were restricted as to how long they could stay in a lane before they had to get out and let another swimmer in (putting their own name at the bottom of the waiting list if they wanted to swim longer).