You have to have a GPS data logger. They usually are about the size of a lighter. You need to sync it with your camera so the time is the same. Then as you are cruising Glacier Bay and shooting pictures, the logger is recording your trip. You think down load the photos and the geo data and it tags your photos with the information of where you were.
I do not have one yet, but am doing some homework to figure out what I need. There is one that also has a voice recorder builtin. Would be nice to be able to record the name of the glacier you are shootin, pen and paper are a pain at times like that.
Here is a link to a Photo related forum.
You will see i am asking a lot of questions about it.