[Turing_Machine]

One of the indigenous boats of the region, the umiak, can be 30 feet long or so and can carry 20 people (or a fair amount of cargo).

They're easily big enough to cross the Bering Strait (in fact, before the Cold War, they did it routinely) and can be constructed completely from local materials (sea mammal hide covering, whale bones and driftwood for ribs -- modern umiaks often use metal fasteners, but traditional ones didn't).

Alaska Natives still prefer them for some tasks (e.g., whale hunting).