I was on Gan for almost two years between 73 and 76. Just before I retired I did a 5 month stint down in the Falklands where I worked with an old colleague who had been on Gan in the late 6os. He told me that he'd had skin problems and had numerous "blemishes" removed mainly from his arms and face. His doctor had told him that 30-35 years after excessive exposure was the optimum time for skin problems to appear. Almost exactly 30 years after my return I noticed a freckle on my arm was growing, then flaking off with nice new skin underneath which then flaked off and so on and so on. So I went to my Doctor who also said 30-35 years was "optimum" and he froze it off. I have had no problems since. I remember when I arrived on Gan in November 73 I went to the NAAFI to buy some sun block (Not available where I lived in November!) and they just laughed at me!