This is a severe overreaction! There are studies that in dense concentrations some of the chemicals in sunscreen can harm corals. But they did not do the work to determine the real world impact.
https://phys.org/news/2019-02-insufficient-evidence-sunscreen-coral-reefs.html
With any chemical, it’s the dosage that matters!
It also ignores the much larger impact of other factors! I have come up from many dives with the bad taste of diesel fuel in my mouth. The oil from the dive boats is a very clear problem that is order of magnitudes greater!
This is like shops banning plastic straws, while still selling large quantities of plastic water bottles! It makes people feel better that they are doing something, but it’s a trivial thing. It would be better to first eliminate the bigger problems that will have an impact!
Other logical problems with the sunscreen arguments.
Lotion is usually an “oily” product that contains the chemicals. Thus it floats! Unless you are diving *under* coral, it’s not going to touch the coral.
For “reef safe” sunscreen, there have not been studies to determine if all of the chemicals in it, are actually harmless. At best they can only claim that they don’t contain the known chemicals.