Ds2 (age4) is a very able swimmer (swimming teachers words not mine) but is still in a beginners swimming class until he "gets used to the structure".
In other words he doesn't listen and follow instructions consistently so fair enough that they keep him with the beginners.
However today at swimming lessons they were doing distance badges. The only ones they expect them to do at ds's class are 5/10 metres with a float. He came out of the lesson with a slip of paper saying he did 5m without a float with lots of !!!! and :):)
Which would be great however he has done 25metres when swimming with me and n his parent and toddler lessons which are part of the same scheme he did 15m and he has the bloody badge sewn to his swimming shorts 
I'm afraid I did struggle to be happy and surprised that he had done his 5m badge.
Now I've got that off my chest I will stop whinging again :)