Presented in an advanced amphibious marine vehicle that incorporates retractable
land drives for operation over beaches or other hard surfaces. In the preferred
embodiment, the land drives retract into hull recesses when the vehicle is waterborne
so as not to add water resistance when waterborne. Power for water propulsion as
well as land drive is normally supplied from the same propulsor motor(s) for simplicity.
Land drives may incorporate tracks, tires, or other land contact mechanisms.