I teach marine biology and have been presenting the traditional model of the equilibrium tidal theory (2 humps on rotating earth) as still presented in most basic texts, but have not been able to find the theory or presumed explanation for the apparent generally increasing amplitude in tidal fluctuation with increasing latitude. (i.e. minimal flux in Caribbean to progressive increases moving up the North American coast to Fundy, etc.). I know Fundy has some special geographic effects enhancing tides, but the New England coast tides are obviously of greater magnitude than those of Florida and the Caribbean, and similar gradient seems evident on the west coast of North America. Can anyone give me some help here??