It was huge, hideous, and its sequence seemed to last almost half the movie. I have never read the original book by C.S. Lewis. Of the Narnia books, I have only read The Lion, the Witch, and the Wardrobe and The Magician's Nephew. A quick glance at a synopsis of The Voyage of the Dawn Treader on Wikipedia doesn't mention any sea monster. In fact, how the sea monster comes about prompted an involuntary chuckle on my part, as it brought to mind a classic, and infinitely better scene from Ghostbusters.
The dragon was so wonderful—couldn't they have just quit while they were ahead?
The Voyage of the Dawn Treader is one of those movies that are entertaining (mostly) while you watch them, but pretty forgettable almost before the credits have stopped rolling. It has pretty people, a heroic wisecracking mouse, a minotaur, and good special effects, but it somehow doesn't quite come together. There are some nice themes that are hovering under the surface: the day when you must put away childish things, having faith in yourself, preparing for death. There are definite religious overtones, but they are general, not too specifically Christian—most faiths have a heaven equivalent to Aslan's land in the east.
With all of those floating ideas I was wondering, while I was sitting watching the movie, why it wasn't adding up to something more. I think what was missing was a sense of wonder. The two leads, Lucy and Edmund Pevensie, are so blasé about landing unexpectedly (yet again) in Narnia, that they made me blasé too, when I should have been a little surprised and excited. Especially when the opening scene with an oil painting emptying an ocean into their bedroom was so very well done. And the under-use of Tilda Swinton was tragic. To see her two quick scenes was almost worse than not seeing her at all. And is she still really such a temptaition for Edmund Pevensie? Is she that gal he'll just never get over?
The Pevensie's annoying cousin Eustace is simply too annoying at first. He was practically unwatchable when introduced—but, then, in comparison to his been-there, seen-that-already-in-Narnia cousins, he actually becomes the most interesting character to watch, and my sympathies and investment in the story completely shifted to him rather than our young hero and heroine. By the end of the movie Eustace had transformed into the most likable character. In fact, I could have done without the Pevensies and Prince Caspian and just gone for a Eustace and Reepicheep the mouse buddy movie.
I can say for the film that it has made me want to dig out my complete Narnia paperback and read the original novel. I'm sure it will have everything that the movie lacked, and I can picture some of the visuals from the film—definitely the best part and reason to go see it in a theater. And I'd like to read Eustace's transformation in more detail and see how he and Reepicheep work out their human/rodent differences.