Yeah. But we are a big county so we are talking seconds! They still very much limited the 200m fly and the LD events by numbers
We were a huge area too - people coming in by plane and ferry!
The 200m Fly and the distance events are always the ones to be limited - one extra heat of a 1500m will take at least 20 minutes, which is a big chunk of your session (which has a limited time).
All swimmers are ranked by speed so the 8 slowest compete against each other etc. and each heat gets faster. By the last couple of heats you will invariably have 1 or 2 14 year olds against a 3 or 4 15 year olds and some 16 and 17 year olds.
Our districts are swum in 12, 13, 14, 15/16, 17 and over age groups (we don’t mix the age groups), 200s and longer are timed finals.
Heats should be seeded on entry times, with the fastest three heats circle seeded. So for 50m - 200 m events the fastest swimmer goes in the last heat, the second fastest swimmer in the second to last heat, the third fastest swimmer in the third to last heat, then the fourth fastest swimmer goes in the last heat etc. You only circle seed the last two heats in 400m+ events.
We have had heats where there's less than 8 and they've all gone through to final but they do race the heat!
That might be because someone has been scratched at the last minute - you would normally swim it as a final in the finals session.