Voith inline thrusters Brian, I have to agree. As prommising as those rim driven thrusters may be, as far as noise, efficiency and simplicity are concerned. But for 24/7 main propulsion, there are not very many out there. I would concider them as a transverse bow thruster or as an swing out steerable stern thruster in a DE boat but not for main propulsion in a yacht or even in a commercial ship. I have seen plans for an retractable rim driven thruster as main propulsion on a racing sailboat but that is actually standby propulsion also. It is still high voltage electricity far to close to water, only separated by one combined seal / bearing. With any kind of foreign object damage on the propulsor, the sealing capacity of that bearing will be affected and your electric motor might have internal raw water cooling . As long as you do not need a really big electrical pod drive (above 5000 KW), I would always keep the electric motor out of the water (like the Schottel SCD or the SRP).