This adopted a similar layout to the Whatsit but had a strut-braced high wing on a blunt-nosed, narrow fuselage pod with a tricycle undercarriage mounted under it.

Its wings had wooden spars and metal ribs and were fabric covered, with triangular endplate fins carrying upright rudders.

It was powered by a 95 hp (71 kW) inverted inline 4-cylinder Menasco B-4 Pirate pusher engine mounted high in the rear of the fuselage.

The resulting Arrowbile, referred to by Waterman as the W-5, was similar both structurally and aerodynamically to the Arrowplane, though the fins differed in shape, with rounded leading edges and swept-back rudder hinges.

Waterman modified a 6-cylinder upright, 100 hp (75 kW) Studebaker unit and placed it lower down in the pod, driving the propeller shaft at the top of the fuselage via six ganged V-belts with a 1.94:1 speed reduction.

This system had been used on the Arrowplane as a safety feature to avoid the commonly fatal spin out of climb and turn from take-off accident but the raked rudder hinge of the Arrowbile provided the banking component even from a nose-down attitude.

[1] The fourth Aerobile was completed as a conventional, non-roadable aircraft; Waterman initially retained the Studebaker engine but in 1941 replaced it with an air-cooled 120 hp (89 kW) Franklin.

[1][4] In early September 1937 the first three Arrowbiles flew from the factory at Santa Monica to the National Air Races venue at Cleveland, a great circle distance of about 2,060 mi (3,315 km).