First - apologize for the lack of a post yesterday.
Second, as you can likely guess from the title, there will be more than one film discussed over several posts.
The movie certainly shows a degree of polish that I would call worthy of an Oscar nomination, but doesn't have the dreck usually associated with the Oscars in it - likely why it was only nominated. The story is well told, the acting is excellent, the overall attention to detail (see the Infogalactic article for departures from the actual events) is outstanding. It tells a tale of six men alone on the ocean, out there because they can be, to prove a point, for the adventure.
The crew itself is an interesting collection, with a background barely touched on beyond "War hero, and legend" for many of them, but included Knut Haugland, a member of the commando team that took out the German heavy water facility in Norway, and Torstein Raaby, who's background is revealed in a bit more depth, and helped guide ally bombers in to sink the Tripitz. This doesn't hurt the film because the story, tight and to the point, doesn't need to dwell on their history much to deal with what's going on.
If I have a complaint, it is this. Early in the story, the point is made by an experienced advisor to follow the native methods in every detail, as they have experience, know what they are doing, or you may lose a leg, or worse. The issue was that to play this up mid film and increase the tension, they created false drama mid-journey involving Watzinger not trusting the methods used that doesn't match the written accounts. Fortunately this doesn't break the movie, and they payoff was actually subtle but very much there, without the movie beating the audience over the head with "see we told you so."
In the end, it's a well told story of six men, being men, facing danger together.