hi,Jenx
I am not sure what age group you are talking about, but I am on my 4th week of swimming with year5.
We have 26 pupils, 8 of these are non-swimmers, the others are mixed between improvers and competent swimmers.
We have 3 staff, 3 helpers (for the coach run) and 3 pool staff who take the competent and improvers.
Usually 1 member of staff goes in the water with the non-swimmers and 1 staff stays poolside giving instructions.
Hope this is of help
Tanya