Do reef-safe sunscreens work as well as chemical sunscreens?

Yes. The active ingredients in most reef-safe sunscreens (zinc oxide or titanium dioxide) block UV just as effectively as chemical sunscreens. The difference is cosmetic, not functional — they can feel thicker and leave a white cast, but as long as you apply enough and reapply, you get the same SPF protection. Find a micronized or tinted formula you like, and you won’t sacrifice anything.