my brother - who has lived in HI for 30 years, is constantly getting cancerous and pre-cancerous crap cut off his face - no freakin thanks says I
so for the last 10 years I've been pretty diligent about getting the sun screen on early - I wish I was as smart as dirtymike and put it on ahead of time at home to avoid greasy hands
I do it at the very start of the day and for the last 5-10 years or so I use Banana Boat Sport 50 SPF (yes, they say going past 30 doesn't make a diff but I say go for the max UV blocking ingredient possible)
I reapply in rub areas where clothes take it off and maybe half way through the day
people see me wearing white long sleeve t-shirts on hot days and often laugh at me - I just shake my head and wonder how they can't have figured out white long sleeves are actually cooler than no sleeves in the sun (white reflects the sunlight while black absorbs it)
here's a cute little number for those that are on the fence regarding which color to wear on the lake