The geared blade design ensures that both blades open and close together. This gives less vibration ahead and astern. Under sail, the blades close simultaneously removing the need for banding the blades together or worrying about one falling open causing an increase in drag.
The 2-blade propeller is available in diameters from 11.5” ~ 18” for shaft and saildrive installations. They are made for both LH and RH rotation installations.
Ahead: GORI efficiency is better than most 2 ~ 3 blade feathering and folding propellers
Astern: GORI has an efficiency equal to or better than most 2 ~ blade fixed, feathering & folding propellers
Sailing: Extremely low drag