Winter at the ocean with a Yorkie.

I have a trip planned for the beginning of March heading to La Push, wa. I will be bringing my 4.5lb boy Sprout with us. I was just looking for any advice or suggestions of things to bring with us for his first winter ocean trip. I will be packing lots of warm outfits and just bought this to keep him dry and keep some of the sand off. Thanks for any suggestions ahead of time!