Abstract: A knock-down boat assembly comprises bow, mid and stern water-tight transverse hull sections, each having fore and aft ends, concave side walls and a transverse bulkhead at the aft end of the bow section, at the fore and aft ends of the mid section and at the fore end of the stern section. The stern section is nestable in the mid-section and the bow section is nestable in the stern section when in the knock-down configuration. The forward bulkhead of the stern section is secured in a position butting against the aft bulkhead of the mid-section and the aft bulkhead of the bow section is secured in a position butting against the fore bulkhead of the mid-section when the boat is assembled for sailing.