So I'll simply say this: SPF 100 is meaningless. Please take my word for it. The key to success with sun protection is reapplication -- that's where most people fail. All SPF 100 does is give you a false sense of security.
A prominent dermatologist just told me this: "I don't care if you use SPF 15 or 500. If you don't reapply throughout the day you're wasting your time."