sun protection

Hi All I know there are a lot of questions here, but I am hoping I will come across someone in the same "boat" as me here :) I have completed the advanced PADI course and the rescue diver one, including about 45 dives or so I will go to the Philippines, Puerta Galera in July for six weeks to do...

I live in Sweden, have a rather sensitive skin in regards to sunburn, haven't been much in the sun this summer and I'm going to Greece to do some snorkelling amongst other things. My gf thinks I should use suncream "like everyone else", me I wonder how much they really protect when snorkeling...