Sun Protection

What to know about sun protection for snorkeling and scuba diving

Frequently asked questions

What is reef-safe sunscreen and why does it matter?

Reef-safe sunscreen uses mineral active ingredients — zinc oxide or titanium dioxide — instead of chemical UV filters like oxybenzone and octinoxate. Studies have shown that oxybenzone causes coral bleaching and disrupts the development of juvenile marine life even at very low concentrations. Chemical sunscreen washes off your skin in the water and enters the reef ecosystem directly. Several popular dive destinations have banned chemical sunscreens entirely. All sunscreen products we carry are free from oxybenzone and other reef-damaging ingredients — you can protect your skin without harming the environment you came to see.Check out our Stream2Sea selection of products, the #1 recommended reef-safe product line.

What does UPF 50+ mean on a UV shirt?

UPF stands for Ultraviolet Protection Factor — it is the clothing equivalent of SPF in sunscreen. A UPF 50+ rating means the fabric blocks over 98% of UV radiation from passing through to your skin. This is significantly more reliable than sunscreen, which degrades in water, rubs off, and requires reapplication. A UPF 50+ shirt provides consistent protection for as long as you are wearing it, with no reapplication needed. For snorkelers spending one to four hours at the surface, a UV shirt is a far more practical and effective choice than relying on sunscreen alone.

Can I wear a UV shirt under my wetsuit?

Yes — wearing a UV shirt or rashguard under a wetsuit is very common and has two benefits. It reduces chafing from wetsuit seams, particularly around the neck, wrists, and ankles, and it makes the wetsuit easier to put on and take off. A snug-fitting rashguard works better under a wetsuit than a loose one. The thermal benefit is minimal — a thin rashguard adds very little warmth — but the comfort improvement is noticeable, especially on multiple dives per day. Some divers wear their UV shirt for the surface interval and simply pull the wetsuit on over it for the next dive.

Is regular sunscreen safe to use while snorkeling or diving?

Most conventional sunscreens contain oxybenzone, octinoxate, or other chemical UV filters that wash off in the water and have been shown to harm coral reefs and marine ecosystems. If you are snorkeling or diving on a reef, we strongly recommend switching to a mineral-based reef-safe sunscreen. Beyond the environmental issue, chemical sunscreens also wash off faster in salt water and require more frequent reapplication than mineral formulas. For areas covered by a UV shirt, no sunscreen is needed at all — which is the simplest and most reef-friendly approach.