We like diving and as a true expedition vessel, we'll be set up for serious diving. We'll also go with aluminium tenders. They simply last longer, give us more design choices and are more affordable then fancy looking RIBS.
This is our aluminium dive tender, a Van Vossen Engineering design. Rugged, built-to-last and with some very unique extras to make boarding a piece of cake.
We plan a 235 HP Yanmar engine with a stern drive. While doing our reseach we ran into some folks in Auckland, New Zealand, a company called Q-SPD International. It's a so-called surface drive.
Supposedly it would bring less maintainance than a stern drive, more speed, less vibration thanks to its Python drive (another Dutch design).
More information on surface drives can be found at this site, also from New Zealand. How come those Kiwi's are so into surface drives?
After several days of waiting for the manufacturer to get back to me on this promising alternative we learned these drive or not very effective at low speeds so we plan to stay away from them. But, for informational purposes, we share the sites we found while surfing the Internet to learn more about 'surface drive' principles. We came accross another manufacturer, Levi Drives. Their page on design issues is informative and worth reading. And here' another list of surface drive manufacturers we ran into. In the US you will find Arneson Industries. The image below, comparing propulsion systems, is theirs. Pulse Drive Systems Intn'l is another company from the US.