In preparation for your trip I would become familiar with the difference in navigating using "North up" and "Track up." I much prefer moving with the map set on "Track up" and using "North up" when working with the GPS in camp.

To keep this simple, using "Track up" will keep my map view matching my surroundings. A bay on my right will be on the right of the map even if I am heading south.

Sometimes the electronic compass will keep the map jumping around. If you hold down the page button you can turn it off and on as needed.

Now to get a little more complicated, you can set at what speed and what duration the compass takes over navigating. I probably have mine set to take over if my speed falls under one k per hour for ten seconds.

Having said all this, my GPS is rarely turned on during most water travel. It is very handy though on island studded lakes where you have to navigate to a hidden bay. It allows me to enjoy the scenery and still go directly to the portage.