An amphibian operable in land and marine modes includes a hull, having a discontinuity, and a retractable wheel or track drive assembly at least partially located in the discontinuity. A wheel or track drive of the at least one retractable wheel or track drive assembly is retracted above a lowest point of the hull when operating in marine mode, and the wheel or track drive is protracted below the lowest point when operating in land mode. The hull is a planing V hull having a forward bow section defining a frontal bow surface/area across a beam of the hull. The discontinuity is provided in the forward bow section, and the wheel or track drive of the retractable wheel or track drive assembly is located ahead of and in front of at least a portion of the frontal bow area when protracted.