In a navigation assistance system, information is received via the Internet from a user pertaining to a water trip contemplated by the user. The system includes a database storing waterway data. The database is accessed in response to the information from the user. At least one recommended over-water route is derived in response to the user information and in accordance with waterway data in the database, the recommended route being communicated to the user via the computer network. The deriving of the route preferably comprises including only route segments extending through operatively navigable areas.