DISCLAIMER: The following is written by a catamaran dealer. Dear Dennis, Regarding your reply (below) to my recent initial inquiry about the two new "pod-type" propulsion systems (and their use in a cat) -- I had the same concerns about the lack of rudders as you, and because I've heard the same problems about low-speed turning inefficienies of rudder-less jet drives. But the pods use propellers, which is quite different. And, what especially caught my attention in this new article in "Power Cruising" magazine (Jan/Feb, 2008) about the Volvo ISP and MerCruiser Zeus pod systems, is that there apparently is an integrated, computer board (optionally interfaced with GPS) between the finger-tip joystick helm control and the twin pod engines. Thus, amazing as it sounds, they claim you can even easily program the steering system so the boat will maintain a "geo-stationary" (unmoving) position in the water (dependent, of course, upon the accuracy of the onboard GPS system). Similarly, if you push the joy-stick, say, directly to starboard, the "computer" will activate each of the swiveling/rotating pod systems, independently AND with their respective props operating at differing RPM (AND with the props probably facing differing directions) so that the boat will move DIRECTLY sideways. Until now, I don't think that's been possible in a single OR twin-engine boat without use of a bow thruster. If the "pod" claims can be believed, a thruster is completely unnecessary. (Handy when trying to fit into -- or move out of -- a tight, alongside-docking situation.) When I say joy-stick, I believe I'm doing these 2 manufacturers a disservice. A joy-stick is what I've seen installed on many sailing cats as an "inside" control for the autopilot. IT is, in fact, simply a "stick". But the control for the 2 pod systems (from what I could see in the well illustrated "Power Cruising" article), is a device (okay, "joy-stick") that ALSO has a circular knob affixed to the "top" of the joy stick. So, you can push the joy-stick in any direction of a circle's 360-degrees -- but ALSO twist (turn) the knob set atop the joy-stick (said knob controls rotation of the vessel). I'm not sure if I've explained this in an understandable fashion, but the end result is waaayyy more directional control than any "mere" joy-stick can provide. Of course, the "harder" you push the stick, the faster the boat proceeds in whichever direction you've moved the stick. Give a small motion to the stick, whether just "pushing" it or also "turning" it, and you get a modest-speed result. Push-n-twist it harder, and you get a faster effect. The article claims even "helm-station newbees" get the hang of it very quickly. (Intuitive as using a computer mouse, I guess.) In addition, both the Volvo and the MerCruiser pod systems employ a pair of counter-rotating props for each pod, so unwanted torque, or "side-walking" effect usual with single-prop systems is eliminated. Don Margraf, the head of my Oakland office is a whiz at the helm of a twin-engine cat. I've seen him "walk" a twin-engine cat, sideways, up a narrow marina channel. I understand the theory: by using differing degrees of throttle with each widely-spaced engine, the "miracle" occurs. (I am NOT a "whizz" at that maneuver.) But these pods systems apparently do something much more magical -- and I don't think I've seen ANY cat (or monohull) heretofore so equipped. Because of the computerized enhancement, if you toggle the stick AND twist the knob atop the stick, the computer will "know" to direct the props in DIFFERING directions, AND direct the props to operate at dissimilar RPMs. I suspect this could only be managed (if no computer were present) by two pairs of hands managing 4 sets of controls at a regular helm. But even then, there'd be no way to know precisely how to "aim" the 2 separate props in differing directions. It's the computer's interfacing with the GPS that apparently makes this possible. (It wouldn't surprise me if the new "automatic parallel parking" now advertised for the Lexus operates in similar fashion.....or maybe it has different "mojo", I don't know.) As to other boaters' concerns about damage to such props -- especially forward facing props -- I, too, was especially concerned about that. Here on Puget Sound we often have an inordinate amount of floating hazards (logs, branches, kelp beds, etc.) The article claims that the pods are specifically designed to break away in an extreme collision, without violating the seal that keeps the hull watertight. Similarly, the article spends time comparing the cost of replacing regular strut/shaft/prop systems (wherein the the boat's hull often also suffers damage, thus requiring lengthy repair) with the (purportedly) quicker-and-easier pod replacement. (Having said that, I've been boating on Puget Sound for more than 50 years, often in fast power boats, I have yet to suffer anything more than a very-infrequently dinged prop blade. But then, I try to be prudent -- I don't speed in the dark, and, as any boater can see, most debris floats in a connected tide line -- so when you see one log or board, slow down because others are most likely nearby.) I also have concern about "computer boards" ANYWHERE on a boat. But, that may well be a holdover from days when electronics WERE often problematic if onboard. Conversely, I've had almost NO problems with any of the electronic navigational systems on my past 3 boats. And nowdays, it's difficult to buy even just a plain-vanilla diesel engine without micro-chips being present in some facet of the engine or its adjoining controls or gauges or operation. Personally, I always like the conservative K.I.S.S. philosophy applied to most ALL aspects of my boating. On the other hand, these "pod" systems are so unusual, and in a way that gives promise of offering a degree of operational control heretofore unknown to us cruising guys that ... well, it's at LEAST darn seductive. And if the truth comes even close to the promise, I'll admit: I'm ready to be "sea-duced!" BTW: I've no personal axe-to-grind in this matter. And the article DID seem to be very "pro" toward these two systems. (A case of "editorial" and "advertising" acting in tandem...?) However, none of the cats I sell offers either the Volvo or MerCruiser "pod" systems. So I have no personal stake in their success or failure. But I'm definitely going to try to find a cat thus equipped. If so, I'll report back. Lastly (and a totally different topic) -- I've just returned (5 days ago) from a 9-day trip to China, devoted solely to visiting a half-dozen boat yards over a 500-mile area, plus meeting with various experts in the fields of diesel motors, marine electronics, onboard appliances interior decorating, etc. If anyone's interested in what's going on there (and it's pretty amazing what those $2-per-hour yard workers are turning out), I'll be pleased to share my observations. My overall observation is that current U.S. and European manufacturers are going to be finding themselves increasingly hard-pressed by the rapidly improving products coming out of China. (I don't think that applies to boats under about 37' or 38' because of the increasing shipping charge, which is too large a percentage of the price of boats under about 38' -- but for boats larger than that?...look out!) I understand even better now why such leading manufacturers as Selene, Grand Banks, Sophie (power cats), Island Pilot 39 mono & Island Pilot 12m Dse solar-powered cat, Nordhavn, Monroe, et al are being built in Asia. The yards are BIG (and growing), the workers highly committed, and the resulting product ever improving. Sheesh, it IS a "brave new world" over there. Rod Gibbons Cruising Cats USA www.CruisingCatsUSA.com > >Message: 8 >Date: Fri, 28 Dec 2007 08:23:02 -0600 >From: "Dennis Raedeke" <dennis@wildmountain.com> >Subject: [PCW] Power-Cat and the Volvo IPS or MercCruiser >To: "Power Catamaran List" <power-catamaran@lists.samurai.com> >Message-ID: <002301c8495d$28b90760$8702a8c0@dennisr> >Content-Type: text/plain; charset="us-ascii" > >I always thought this type of drive would be great until you come to the fact >that there is no rudder. Even with the big rudders on Wild Wind IV, running >down wind keeping your course requires a lot of steering. It's fine if you can >run fast, but you can't always do that. I spoke to a power-cat ferry skipper >on the east coast. His boat had jets and no rudders. He stated he almost lost >his boat on several occasions because of the lack of rudders. > >I guess you could add them. That would take some efficiency away. > >As with everything else, one type system doesn't fit all. > >I think it's great new technology now that they are coming out with it in the >size most of us can use. When I researched this years before, it was only >available for big applications. > >Regards, > >Dennis

Hi all If the links don't work, search "Volvo IPS" on YouTube.com for videos / demos http://www.youtube.com/results?search_query=Volvo+IPS&search=Search and for "Mercruiser Zeus" http://www.youtube.com/results?search_query=Mercruiser+Zeus&search=Search Roger Bingham France

Rod Gibbons wrote: "I've been boating on Puget Sound for more than 50 years, often in fast power boats, I have yet to suffer anything more than a very-infrequently dinged prop blade. But then, I try to be prudent -- I don't speed in the dark, and, as any boater can see, most debris floats in a connected tide line -- so when you see one log or board, slow down because others are most likely nearby." Rod, I know what you're saying, but in ten years of boating here in SE Alaska I've hit two smaller logs which caused minor prop damage but kicked up my outboards, a submerged 'mystery' object which was never identified but kicked up the outboards. I also have encountered the bottom twice (one 100% my fault, the other due to gross chart inaccuracy) which caused $3,500 in lower unit damage, though I was able to come home under my own power because the outboards kicked up thus preventing further damage. I've also passed numerous larger logs floating nearly submerged which were impossible to see looking forward with glare or chop on the water. And then there are all the whales up here... Perhaps I'm a reckless maniac out there, but I don't think so. My friends view me as being overly cautious. Maybe it's been repealed on the East Coast or in Puget Sound but Murphy's Law still reigns supreme around these parts. Installing a boat with an unprotected propulsion system like the IPS would be akin to pinning a 'Kick Me' sign on my back, IMHO.