Hey, You need sunscreen if you go on a glacier tour, snow reflects the suns rays and I have gotten some nasty burns skiing!
A good light weight jacket that is waterproof, and a fleece pull over are a good idea, you can layer it with the jacket or if it's dry just wear it. I'd remeber the swimsuit for the hot tubs, and formal night is still formal! Some slacks for the ladies( even if your not a slack fan) and a sweater, and do pack one pair of shorts, you may hit a sunny day. When are you going, July and August it can have some warm( not hot ) weather 70 -75, sept to october it can cool down quite a bit.
Number one thing to bring is BINOCULARS, there is so much to see on shore, you will never regret bringing them!