In 1930 Portuguese government authorized the new fleet revitalisation program. Among the ships that were ordered in Italy there was a 5110 ton seaplane carrier. However in 1931 the Italian orders were cancelled and while submarines and sloops were re-ordered in Great Britain, the seaplane carrier project was abandoned. I was able to locate a schematic plan of this project which was the source for the drawing below.
Here's some technical data:
Length O/A: 140.4m
Beam: 18m
Powerplant: 12,000 SHP
Speed: 22 knots
Range: 8,000 miles at 12 knots
Armament: 4x120mm/50 (Italian guns, OTO mod. 1931) , 4x76mm/50 (British 3" QF), 4x40mm/39 (British 2-pdr)
Aircraft: 12 seaplanes
I chose CAMS 37 seaplanes as they were used by Portuguese Naval Aviation at the time. Also I've sprinkled the drawing with some minor details that were not visible on the plan.