To Alaska by ferry from Washington State?

You can take the Alaska Marine Highway ferries from Bellingham to Juneau without changing boats, however, the run from Bellingham to Ketchikan is a long one. You might consider a cabin for that leg. Some problems might be the ability of your refer to keep food as LP must be off and sealed for you to be aboard the boat. Also, pets need to stay in the RV and you cannot access the vehicle unless it's in port. Just about all the route is in protected waters. On a different boat the trip from Juneau to Whittier is mostly in open Gulf of Alaska waters and can be rough. Pet and LP policies are the same and a cabin might be desirable for that run too. The ferries are a great way to travel with good meals served cafeteria style that are quite reasonable. Comfortable seating is available and lounges are also on board for those who care to partake. Go to http://www.dot.state.ak.us/amhs/routes.shtml to start learning about the Marine Highway