The feasibility of providing complete treatment of human waste by means of an incinerating toilet small and inexpensive enough to be suitable for use on small pleasure boats was investigated. A toilet that avoids the need for an auxiliary power supply by relying on natural draft was built. Its performance and the quality of its effluent were evaluated. The quality of effluent, both exhaust fumes and residual ash, is acceptable. However, the natural draft is unreliable, and the heat input needed to eliminate all odor from the exhaust fumes is greater than the unit can efficiently dissipate. The unit as constructed could potentially act as a source of ignition for explosive vapors originating elsewhere on the boat. A redesigned unit was constructed to burn with a forced draft at a lower temperature, and to use a catalytic oxidizer to eliminate odor from the exhaust fumes. An explosive vapor detector was designed into the circuit to eliminate the possibility of igniting extraneous vapors. This unit has not been tested and evaluated.