Waldo Waterman bought six surplus Boeing model C seaplanes for $250 each. Their ordinal engine was a 110 hp Hall-Scott A7A. This four cylinder had a bad reputation of vibrating badly and catching on fire due to broken fuel lines.
These seaplanes were converted to land planes.The aircraft in this photo has been modified to carry four passengers forward of the pilot. The seaplane's wingtip floats were repurposed as fuel tanks attached to the underside of the top wing.
The engine in this aircraft is a one-off modification of a 230 hp Salmson Z-9 by Waldo Waterman . The Z-9 was a water cooled radial. Waterman manufactured air cooled cylinder for this engine. The water jacket was removed and copper cooling fin were brazed on. Since the engine was French it used a right handed propeller. Waldo used a prop off of a Curtiss HS-1L flying boat which had pusher engines.
Waldo used the aircraft for an early airline service from Ontario, CA to Big Bear Lake, CA.