Alaska Marine Highway
The Alaska Marine Highway (AMH) or the Alaska Marine Highway System (AMHS) are a network of ferry lines connecting destinations along the southern coast of Alaska and going all the way down to Bellingham (Washington). It provides a connection to many island and island-like communities, including the Alaskan state capital Juneau which is accessible only by boat or plane despite being located on the mainland. The AMH is also an alternative to the long drive through Canada for overland travel between the lower 48 states and Alaska, and can be a more affordable (if decidedly less luxurious) way to witness some of the same rugged coastal scenery that Alaskan cruises take in.
Understand
The Alaska Marine Highway (System) is operated by the State of Alaska and comprises 3,500 miles or almost 6,000 km of ferry lines. The system connects 32 ferry terminals from Bellingham in Washington state to Dutch Harbor in the Aleutian Islands, but unlike its Norwegian equivalent Hurtigruten you're not able to sail all the way between these places onboard one boat. The system is divided into three parts; Southeast Alaska south of Yakutat, South Central Alaska around the Prince William Sound and Southwest Alaska including Kodiak and the Aleutians and the three parts are not as well connected as you might expect, especially outside the summer season.
Prepare
Current schedules are available here, both as a sailing calendar showing arrivals and departures on a current day, and as a colored grid showing routes. When planning your trip you may also want to have a look at a map of the system.
Get in
Many of the communities on the Highway are served by plane, and some (but by no means all) are served by road. The southern end of the system, Bellingham (Washington), is near Seattle and Vancouver which both have quite good road and rail connections from the rest of the US and Canada, and by plane from even further away.
Elsewhere, the only major airport is in the state's by far most populous city Anchorage with services from the rest of the US and in the summer also from Europe and Asian Russia and moreover the city is connected to the rest of Alaska by road and rail with the Alaska Railroad offering service pretty far inland. Perhaps surprisingly, AMH does not serve Anchorage but relatively close (considering this is Alaska) Whittier, about 60 mi (97 km) away.
Sail
The information below is derived from the AMH schedule as of September 2017 and is just a general overview and might change over time. Check the current schedules for current routes, frequencies and ships.
Southwest Alaska
Communities west of Kodiak Island are only served during the summer months, about twice a month. Destinations on Kodiak Island are connected to each other and to Homer on the mainland about three times a week during the winter and almost every day in the summer.
South Central Alaska
Homer is the starting point for boats to the Aleutian islands but except for the MV Kennicott that calls there about twice a month during the summer months (going all the way to Bellingham) you can only choose between plane and road to get east from there.
The largest ports in the Prince William Sound; Whittier, Valdez and Cordova are connected to each other on a near-daily basis around the year. However the only connection to the southeast from there is the aforementioned MV Kennicott.
Southeast Alaska
Juneau is the ferry hub of Southeast Alaska with all lines calling there. There are four shorter lines in the region all operated by the same ferry (MV LeConte) and each running once a week; Angoon-Tenakee-Juneau, Pelican-Hoonah-Juneau, Gustavus-Juneau and Juneau-Haines-Skagway.
Southwards there are three lines, known as the mainlines. The one starting from Bellingham goes via Ketchikan, Wrangell and Petersburg to Juneau and onwards to Haines and Skagway and runs once a week. The second line beginning in Prince Rupert also calls at Kake and Sitka on its way to Juneau. It runs approximately twice a week with some ferries going all the way up to Skagway. Finally MV Kennicott; the ship plying the longest route, goes from Bellingham via Prince Rupert, Ketchikan and Juneau up to Yakutat and onwards to South Central Alaska crossing the Gulf of Alaska (though unlike the both other mainlines it runs only in the summer).
See and do
Enjoy the Alaskan scenery from the observation lounges. Other than that, the ships often have a movie theater and a solarium.
Eat
Eating options are not exactly comparable to cruise ships, but there are cafeterias on board the AMH ferries. You can also bring your own food, there are coin-operated microwave ovens available for heating.
Sleep
Cabins are available on the larger "mainline ferries" Columbia, Kennicott, Malaspina, Matanuska and Tustumena. There are in general two- and four berth cabins to choose from. Day boat ferries making shorter trips don't have cabins.
Stay safe
Alaska enjoys a low crime rate, and onboard the ships it's probably even safer than on land. Sea sickness may become an issue on segments crossing the open sea.
Go next
For most stops, your choices of places to go next to is very limited; you can either continue with the AMH or fly out on a small plane. The exceptions are most harbors in South Central Alaska, Haines, Skagway, Prince Rupert and Bellingham.