Many sailors would like to have a 'retractable propulsion system' to eliminate that excessive drag of conventional 'fixed' prop/shaft systems. There have been a number of different systems worked on in the past few years, but mostly custom systems that have not reached any production status. I even suggested one utilizing a 'rim drive propulsion unit' , http://www.runningtideyachts.com/dyn...Rim_Drives.php .....but development efforts on these rim drive units dropped off significantly during the depressed yachting market following 2008. Just to clarify, there is a distinction between the '(bow)thruster units, verses the propulsion units. The thruster market has progressed along, but little work has been put into the propulsion units. I was just doing a little research on retractable propulsion units and ran across this mention: http://www.shippingandmarine.co.uk/a...39&issueid=454 Anyone know where we might find some photos and more details on these units?