Why sunscreen alone fails on the water, what reflected UV does, and how to cover the spots anglers actually burn.
Water throws UV back at you
Open water reflects a meaningful share of ultraviolet light straight back up. White sand does it too. That is why people burn under their chin and on the underside of their nose on the boat and nowhere else, and why shade alone does not solve it.
Sunscreen has a working life of about two hours
Less with sweat, spray and wiping your hands on a towel. Reapplying every two hours across a nine-hour day means five applications, and almost nobody does that. Fabric does not need reapplying.
Cover first, then screen the gaps
The efficient order is a hooded UPF shirt and sun gloves, then sunscreen on the face and anywhere still exposed. That turns a whole-body job into a small one you might actually keep up with.
Cloudy days still burn
Cloud cover cuts heat far more than it cuts UV. The days people get caught out are the mild overcast ones where nothing feels like it is happening.