Hello,
If you’re looking for reef safe sunscreen, I was able to find one at Superstore. It met the guidelines of the Save the Reef website. https://savethereef.org/about-reef-save-sunscreen.html
It’s Live Clean Sport mineral sunscreen. It’s not cheap at $17, but is one of the cheaper ones out there. Bonus points for being made in Canada. But is a 113g size, which might be an issue if you want to fly with it in your carry-on. https://www.realcanadiansuperstore.ca/suncare-mineral-sunscreen-lotion-sport-spf-45/p/21174496_EA