A wakesurfing boat and a hull for a wakesurfing boat. The hull includes a bottom having a preselected length extending from a bow to a stern. The bottom includes a central ridge and port and starboard ridges extending below respective port and starboard bulwarks to define a substantially M-shaped bottom with concave portions to port and starboard of the central ridge. Port and starboard sponsoons extend below the port and starboard bulwarks proximate the stern. A trim wedge projects below the stern. Two rounded stern portions are provided proximate the stern. In a dynamic surfing mode, with selectively-fillable ballast tanks partially or fully flooded, water flowing through the port and starboard concave portions, combined with the ballast, increases resistance to the hull, resulting in a larger wake wave. Water passing around the structural features proximate the stern is directed toward a convergent zone in the wake, resulting in an improved wake wave shape.