I know there are such things available I’m sure so if you can find an spf rating you would be better off

There is a brand called Platypus Australia which has some great swimwear for children – it is a little pricey though.

When it comes to my kids, the spf on outdoor clothing is sonething I look closely at

I look for ratings on all products and also limit the amount of time in full sun – avoiding the hottest time of day which still leaves plenty of time for outside play and swimming.

I’d look for SPF ratings as well as how much of the body is covered by the rash.