Abstract: A collapsible boat whose lateral hull walls are retractable to reduce the width of the boat is provided. Port side and starboard side lateral hull walls are pivotally connected along their lower edges to the central hull section of the boat. When extended, the lateral hull walls form a sloping hull wall extending upward and outward from the bottom of the central hull section. When retracted, the lateral hull walls pivot inward to reduce the width of the boat. Port side and starboard side braces are pivotally connected to the upper lateral edges of the central hull section for movement between an engaged position and a retracted position. In the engaged position, the braces connect to the lateral hull walls to keep them in their extended position. In the retracted position, the braces are pivoted inward to allow the hull walls to retract.