I read the book and watched the movie, but I still don't quite get the point (if any) CS Lewis was trying to make in 'Dawn Treader'. Narnia:VDT reduced the vastness of the Narnian conflict of the previous two movies down to an Amazing Race-style scavenger hunt on board a Pirates of the Caribbean wooden vessel. While the change of scale made for more focused storytelling, the plot felt like a series of episodic challenges in a checkpoint-to-checkpoint run with a souvenir to collect at every stop.
Now, scavenger hunts are fun, especially when the seekers don't always act in unison; argue and bicker a lot; and vent their frustration over their or their teammate's incompetence. That's why we like watching the Amazing Race so much. But I've come to expect that the conflicts in Narnia are bigger than that.
Narnian conflicts are clashes of wills between implacable foes that scheme and strategize against one another. Both sides are usually fleshed out, their natures explored and agenda laid bare. But VDT is more one-sided, POV firmly fixed on the Treader crew while the audience isn't sure if the antagonist has an agenda or is even intelligent in any way. There are no hints as to its plans or ambitions other than randomly capturing hapless Narnians and keeping them together aboard longboats awaiting... what? Rescue?
Perhaps this installment was just meant to introduce a new player in Aslan's Grand Design: Eustace, the skeptic. A disbeliever, a complainer, has a scientific turn of mind but totally unimaginative because of it, Eustace starts out quite useless to anyone. It isn't until he learns how fallible he is, and how dearly his mistakes have cost him that he grows to eventually become the salvation of the Treader's crew when times are darkest.
Oh, wait. Maybe that is Lewis' point right there. Conflicts are not always large-scale; often they are personal and internal. Threats are not always definable, yet they are no less dangerous if left unchecked. The key advice for the crew is not to give in to temptation -- mostly the temptation to strangle Eustace. As for Eustace, Aslan can find redemption for even him and turn him from impediment to a key partner in the Treader's success.
Despite not being too impressed with the overall storyline, the going home sequence has never failed to get to me. At this point Aslan finally shows up and commends our heroes for a job well done, then rewards them by returning them to their drab, mundane, everyday existences, occasionally telling them they can't come back. Regardless, they're a little stronger, wiser and more able to deal with life's curveballs for their experience. If handled well, crisis will do that to you every time.