I'm not much for sea stories. I tried hard to read Patrick O'Brian's Captain Aubry series, but I couldn't even get through Master and Commander, the first one. I just didn't understand what was going on. The only real sea story I've ever loved was Voyage of the Narwhal, and that primarily because of the psychological exploration of the men in the crew.
So I approached Dark Voyage with caution. I've heard so many wonderful things about Alan Furst. He is a "superior chronicler" of World War II, and this book in particular got astounding reviews. It took me a long time to get into it. There was a real "should I or shouldn't I" moment when I was afraid I would give up on it. But I think what kept me going is that the writing was beautiful, and the main character DeHaan was compellingly drawn. He never gets too mushy, as he shouldn't about a merchant ship's captain, and yet you get a deep view of the internal workings of DeHaan's heart and mind.
Eventually, I was drawn in, and boy was I. By the last 1/3 of the book, I was sitting on the edge of the couch and shushing my husband if he tried to interrupt. One of those books where you'll say "sorry, sorry, I'll start dinner in a minute". You may have to tolerate, as I did, not exactly knowing what was going on in the beginning. But it's like a snowball that gains momentum and I was sorry to turn the last page.