Casual chat about experience, then an assessment of the teaching in the pool whilst they watched and the other teacher is there as assistant to help. They were very nice and understood I had a lot of experience. they were more interested to see how i was at teaching in the water.

Short - just ensuring that you are comfortable teaching. Met in the cafe, 1 to 1 interview. Friendly, calm atmosphere. If you are a qualified swimming teacher, and they have contracted hours available, it is likely that you will get them.