Occupational sunlight exposure and melanoma in the U.S. Navy (pubmed.ncbi.nlm.nih.gov)

I wouldn't want to over-state it, but I see parallels here to radiation hormesis, in that some amount of sunlight is beneficial because it stimulates vitamin-D production which itself is protective to cancers, as well as mental health and bone density.

"no safe limit" take note.

I wonder if they managed submariners differently? They used to be supplied with UV lights inside the vessel.