The TYPE V.80 was a somewhat enlarged version of the VB.60 and it had a 10kw auxiliary electric motor which drew power from a battery. The boat was completed in early 1940 and employed under the State Service Flag, undergoing trials to test the feasibility of the Walter Propulsion System. Like the VB.60, a figure-eight hull form was used in the midships area, but with a short second cylinder placed below the main pressure hull which would be the tank for the Perhydrol fuel. V.80 was paid off at the end of 1942 and placed in reserve.

Displacement: 73 1/4 tons/76 tons
Length: 72' 3"
Width: 7"
Draft: 10' 6"
Machinery: single shaft Walter geared turbine
Power: 2,000 SHP
Speed: 28 knots
Auxiliary machinery: electric motor
Auxiliary power: 14 SHP
Auxiliary speed: 14 knots surfaced; 4 knots submerged
Bunkers: 20 tons of PERHYDROL
Radius: 50 miles @ 28 knots

(HARRY'S NOTE - it was this lack of efficiency that ultimately made all Walter-powered boats unusable for combat - they had 'very short legs' for sustained combat.)
Tubes: none
Guns: none
AA Guns: none
Crew: 4