I find Ultrasun confusing. I did read somewhere that they were not allowed to put 'once a day' on the bottle but if you read the leaflet that comes with it, although it is water resistant it does say to reapply frequently too. It also mentions your skin's sun quota ie how long you can stay out in the sun before burning stating that this was once a day (only sunbathing once a day according to your max sun exposure is my understanding).
After reading the whole thing it really didn't come across as 'once a day' product at all as it never mentions it.
Would be interested in anyone else's interpretation of the leaflet as I did purchase the Anti-aging face duo but returned it because of the confusing information.
By the way TX Maxx had the SPF20 for £9.99 if anyone is interested.