We will be departing Vancouver and doing the Hubbard Glacier tour on the RC Radiance of the Seas at the end of July. I was wondering just how cold does it get during this time of year. We currently live in Florida and our bodies have gotten use to the warm weather. I contantly hear of layering but just exactly how many layers do you need? Would a sweatshirt, t-shirt and light rain jacket be suffice? Also, what kind of footwear is best? Thanks in advance.