Vetus has downsized the integral tunnel-motor bow thruster so that it will fit on boats as small as 45 feet. There are two Rimdrive models, the RD125 and the RD160, which both have internal tunnel diameters of 9.8 inches and are rated at 8hp and 9.6hp respectively. The propeller and the outer ring connecting the tips of the blades also serve as the motor’s rotor, and the stationary windings are in a tunnel module that slides into a boat’s structural tunnel tube. As a result, there is no bulky motor to install inside the boat, only a compact interface module. Also, because the “motor” is submerged, and therefore water-cooled, the only limitation on run time is the capacity of the battery bank. Vetus claims its multiblade propeller is virtually cavitation free and that the motor is almost silent. The Rimdrive also operates at variable speeds so that thrust can be adjusted to suit conditions, making short noisy bursts of power a thing of the past. Price not available. Vetus Marine, vetus.com
