To explore Belize with two kids of age 4 and 6 for a day, our safe bet is Lamanai in northern Belize. Transportation would take bus north closed Belize boarder and take boat down New River to Lamanai.
This is a 7-Day NCL cruise from Houston with port of calls: Cozumel(Mexico), Belize City(Belize) and Trujillo (Honduras). In November, West Caribbean temperature isn’t hot nor cold and weather is in a sweet spot for water activities.