According to sleeps.com, dreaming of boats signifies:

The boat is a dream symbol for your life and/or business, and the dreamer must pull together all the aspects of this dream to approximate the meaning, such as: the water, whether it is clear, murky, inland lakes, or oceans, was the boat moving, etc.

According to avcweb.com, a boat journey in a dream represents your life journey. djmcadam.com specifies that boat journies signify fortunate journies.

In the movie The Cell Jennifer Lopez's character ("Catherine Deane") urges her first patient ("Edward Baines", played by Colton James) to construct a boat and sail out of his coma. At first he constructs a toy boat but she tells him that they won't fit so he upgrades it. It should be noted that all of this takes place in a desert, therefore in order to sail away he also must bring the water. Anything more and this would become a spoiler.