Monohull verses Multihull powersailers / motorsailers

Discussion in 'Motorsailers' started by brian eiland, Aug 8, 2004.

  1. brian eiland
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    brian eiland Senior Member

    MITseaAH, BIG motor sailer

    I did feel this tread subject wandered off the path a few times. Now I'll post a letter I recently wrote to the creators of the new 156' MitSeaAh motor sailor. I think this discussion is more closely related to my original posting that started this thread.
    Liebowitz & Pritchard
    Washington, NY

    Pedrick Yacht Designs
    Newport, RI

    Dear Sirs;

    I was just looking thru the latest BOAT USA International mag (Mar/Apr 05 issue), and came upon a sizable article about the new “MITseaAH” motor sailing vessel. This unusual and challenging design is receiving quite a bit of boating press at present, and apparently a lot of interest at this past years’ Ft. Lauderdale boat show. There was also a very good, extensive article & illustrations in the Apr 04 issue of Yachting World.

    What I find particularly interesting is the fact that an owner of a power vessel (and 5 previous ones) would commit to a new vessel design with a sailing rig on it!! Usually it’s the other way around, a case of an older sailor finally converting to a power vessel. Sure wish I could find such a progressive individual to consider building my power-sailing, gamefishing/motorsailing design

    I applaud most all attempts to resurrect the motorsailer concept, as I feel it has been a sorely neglected subject in this modern boating world. Witness again my website reference,, and the attached document I created for this past year’s Miami BoatShow, “Motorsailing Catamaran Concept”. The latest doubling of the crude oil prices might just spur more developments in the motorsailor arena.

    Back to the subject of the vessel “MITseaAH”. I really can appreciate the extraordinary efforts on the behalf of the creators of this vessel. They were really challenged to develop solutions to a tough number of requirements by the client. And they managed to come up with some very unique solutions.

    But here I would like to offer an alternative solution to satisfy that owner’s requirements. First lets look at some of his major requirements:

    1) the sailing rig needs to pass under a 127' high bridge for visits to the Statue of Liberty
    2) shallow draft to be able to moor in front of his house on Long Island in water of 7 foot depth
    3) shallow draft to visit some of ‘his favorite locations’, and ‘root out those shallow anchorages’
    4) top speed under power of at least 25 knots
    5) sail well & power well (I think the ‘sail well’ portion was an added challenge of the designers)
    6) accommodations for owner and up to ten guest
    7) maximize usable deck space for guest
    8) luxury of his present yacht

    I submit that all of these requirements could have been met by a 100-120 foot catamaran
    motorsailing vessel. For an example have a look at “Douce France” <> , <> . Now this vessel utilizes a two-masted ketch style sailing rig that might seem a little complicated for an owner not accustomed to sails. How about if we replaced that with my ‘single-masted ketch’ rig. <> Everything roller-furls, no hoisting of sails, no stowing of sails, nor extensions of the mast height, a much more simple rig to build and operate. At the 127' upper limit it would look ‘in proportion’ (aesthetics) on a catamaran from 100 to 120 feet. And its lower center of effort (than a sloop) could allow for the use of a smaller beam to maintain sailing stability.

    With reference to the subject of stability look at the massive efforts and expense on MitSeaAh. A 15 ton lead bulb, suspended on a stainless fin keel (total 24 tons), that pivots up on precision-machined bearing blocks from a 21 foot draft to 7.5 feet. Special hydraulics to raise and lower the keel, as well as special hydraulic vaporizing considerations to account for the ‘accidental grounding’ of this huge assembly. And then a big hole up in the accommodations to accept the retracted keel. All of this is totally unnecessary on the big catamaran, as it gains its stability by a spread-out- form, saving tons of weight, cost, and complication, and damage potential. Plus we don’t need stabilizers at all, nor their complications, particularly those autogyro-controlled flaps on MITseaAH. And our draft could be as little as 4.5 to 5 feet.

    There are also a few massive efforts expended to attain a powering speed of 25 knots; two huge 12 cyl 3500 hp diesels, 204,000 gal fuel supply tanks, Servogear, computer-controlled, variable- pitch 5.4' dia props, and a very complicated bottom configuration with recesses to accommodate the big props, plus huge hydraulic rams to control the two vast trim tabs extending across the whole width of the transom, and finally a complicated retracting rudder system to operate in the area of these trim tabs. Sure sounds extremely complicated , expensive, and HEAVY. That much HP, and that much fuel, reminds me of another article I included in the archives of my website, “The Need For Speed”, wherein there is a discussion of the ever spiraling need for bigger engines to carry the ever increasing load of fuel required by the bigger engines. (in this case for some modern game fishing vessels).

    I would venture to guess that the alternative big catamaran design might have only required twin engines as small as 600 HP.....or lets go with a big extra margin and chose twin 1000 HP’s. Total, 2000 HP verses 7000 HP!! Quite a difference in fuel needs, weight needs, space needs, and propulsion gear sizing and configuration. And what about all of that extra aux power required to run the hydraulics required for MITseaAH’s trim tabs, auto-gyro flaps, controllable pitch props, keel control, extendable mast, etc, etc I know which vessel I would rather be charged with maintaining in good working order.

    Please excuse me just a moment while I digress to consider the fuel needs of these big engines. The owner looks forward to trips from Long Island, NY and Newport, RI to Bermuda. I believe it has been estimated that MITseaAh will burn about 60 % of her fuel load on this 25kt dash out the 630 miles from Newport to Bermuda. That works out to about 122,400 gal or about 200 gal/mile. At an average approaching $3.5 per gal (between here and Bermuda) this trip will run about $428K per one way trip. I’ll bet we could have cut this bill SUBSTANTIALLY with the catamaran hull form. And we might have been capable of maintaining a higher average transit speed in adverse conditions.

    Per the requirements for 10 guest (5 staterooms) plus owner, and lots of deck space, I don’t think there is much doubt this can all be achieved in the catamaran; and in very nice privacy manner. Luxury can be provided as well, particularly with attention to light weight construction as desired by the multihull vessel, and utilized on MitSeaAh.

    Excessive beam is the one attribute of a catamaran most sighted as a negative aspect, particularly in finding docking space. But in this case I detected an owner willing to ‘moor’ his vessel in front of his home, and I imagine he might be willing to do so in Bermuda, Newport, Nantucket, etc when available dock space is limited, or NA on short term notice. He has the toys onboard, and the nice stern boarding platform to make this connection with shore readily accessible.

    As I look back over this letter I almost feel the need to apologize for the negative overtones I’ve conveyed on MITseaAH. On the contrary, I really appreciate the efforts of her creators to solve the problems and produce a very unique new yacht. I can only hope the next time they are presented such a challenge, that they give some consideration to the catamaran vessel form.

    Brian Eiland

    Attached Files:

    Last edited: Apr 11, 2005
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    FAST FRED Senior Member

    "Excessive beam is the one attribute of a catamaran most sighted as a negative aspect, particularly in finding docking space. "

    Sounds like this bucket in Cat form would have to pass up on St Georges , the great spot to stay in Bermuda , as the channel in is quite narrow.

    Shame to miss Doubble Diamond Ale , and ICE CREAM, in the same shop , only to have to put up with the commercial port with the great view of the cruise ship sides.

  3. cyclops
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    cyclops Senior Member

    When efficency is raised all we need do is to look at the "new" ferries. Cats. When nostalgic times are needed , power and sail. You can not have a past form and modern design in the same boat. Any attempt to such a design relagates the designer to a person who needs the money.
  4. brian eiland
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    brian eiland Senior Member

    Monohull Motor Sailers, Motor Sailors

    Several of my postings on this subject thread had been rather critical of a couple of new motor sailer designs. This posting counters that negativity, and introduces a real good article on monohull motor sailors I ran across as I was researching MITseaAH. This was written by Greg Jones of BlueWater Sailing magazine so I will not copy it to this posting, but rather give a couple of brief excerpts, and then tell you the site address were you can read the full text if the subject interest you. I would recommend it.

    The first one is, "Motorsailers, The 50 percent solution"

    by Greg Jones
    The new generation of motorsailers might be the biggest design evolution since the Bermudan rig. Motor sailing is the dark secret of most cruisers; ask any cruiser how often they run the engine while sailing and the answer may surprise you, given that they are on a sailboat, designed to make way without the use of an engine. But the reality is that regular use of the engine is almost a necessity, even with good and fair winds. Primary among the reasons for this, apart from driving the boat, is the need for electricity. While some cruisers run their genset instead of the engine, it is still nice to get that extra few knots out of the boat, and the engine prefers to have a load on it, so why not engage the prop and get to that palm-lined island a few days quicker?

    …big snippet…..

    We are not going to go out on any limbs and say which is the best motorsailer. Even more than with sailboats, the design dictates what the boat does best. Sailboats only have to sail, but motor sailors have to perform well with two very different motive forces. When done right the solution results in a boat that is comfortable, relatively fast (or at least consistent) and has more room than a comparably sized sailboat. There aren't any "pocket" motorsailers as the design requirements virtually assure the boat will be big enough to be comfortable in a seaway. With a design that provides an easily driven hull and adequate sail area, the boat will derive maximum efficient speed from each. This will reduce fuel costs, and the smaller sail area will be easier to handle. Today's motor sailers are evolving quickly, driven by more knowledgeable owners and designers who derive inspiration from the best boats of the past and improve them with modern design technology and a sure eye


    The second one is "Motorsailing with Design Honesty"
    (BE notes: sort of a sales pitch for Ted Hood’s design)

    by Greg Jones
    Most cruisers spend a lot of time motorsailing. This is the dark secret of cruisers; with the larger engines now being put in cruising boats, cruisers often fire up the cast iron gennie whenever their speed falls below, say, four knots. This allows them to plan their voyages with greater accuracy as regards arrival times and passage durations.

    This evolution of use has resulted in more motor-sailers being designed that are good sailboats to begin with (as opposed to being motorboats with a small rig), and the latest design from Ted Hood's Portsmouth Marine, the No Compromise 54, is exactly this sort of boat……

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    FAST FRED Senior Member

    There is NO question that a boat with a "multi hull" style hull, light and long and skinney will be the easiest to push thru the water.

    But why bother with a Capsizing Cat ?, when the same building costs will get a FASTER monohull boat , although longer.

    Sure Cats are great Roomarians and make great dockside cottages , but the VAST wetted surface makes for really slow going in light airs and costs boodles of power at speed.(Tho perhaps less than the current power boxes)

    The RV Triton style cruiser would seem to offer the best compromise in an offshore motorsail that is fast , ez in fuel

    and COULD RIGHT herself after a CAPSIZE!

    Could be YOUR but in those 46- 70 ft waves off FLA!

    The Kite rig will alow fast sailing sans big stability requirements ,
    and location of the mast where it can be used as cargo boom ect.

    "ONLY Fools & Yachtsmen Beat to Windward" not Motorsailors.

    How am I wrong?

  6. brian eiland
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    brian eiland Senior Member

    This was my answer to Mr Greg Jones:
    Hello Greg,
    Just finished reading two articles you wrote on motorsailers, and I can tell you are ‘hooked’ (to use a fishing term) on them as much as I am. Right up front I would like to compliment you on your “50% Solution” article. I liked it better than any other I have seen that tried to define this potentially very broad spectrum of vessels…..very comprehensive and fair as far as the monohull versions are concerned. You just left out the most modern versions based upon the multihull form.

    I really can appreciate a lot of these new ideas in the ‘motorsailer theme’. I believe that many marketing people are waking up to the reality that the already small sailing population is on a decline and gravitating toward faster cruising forms in power and/or sail. Some of this is a result of the older population deserting sail for a trawler. Some of this is the younger population not content with slow cruising in this fast paced world….they may only have the weekends to work with.. I think some of the renewed interest in the motorsailer concept is the result of these observations…so they say lets add some more OOMPH in our sailboats. But be cautious, that does not a motor sailer make.

    Adding a bigger and bigger engine (or twins) is not the most efficient solution, although it does more truly exist as a MOTORsailer. As you said, “A big engine will only mean you will be able to maintain speed in adverse conditions: You won't go any faster” I think you made a very important observation, “Accept that the virtue of a motorsailer is that you can make higher average speeds, which is done by eliminating the slow speeds and continuing to make decent way even in the absence of wind”. In other words bigger engines for faster top end speeds aren’t the answer in defining the monohulled motorsailer, even thought the marketing guys would have you believe so. And the real virtue of twin engines is maneuverability and ‘back up’ propulsion source. But wait a minute, in a motor sailer our back up propulsion source is the sailing rig, so twin engines is overkill in most situations.

    I start to see a trend here similar to what is happening in the trawler world. There seems to be an increasing demand by the public for just a little more speed than that offered by the truly efficient displacement trawler. So now we see more and more twin-engined trawlers, with greater and greater HP, that in reality are going beyond the definition of trawler…they are becoming motoryachts in trawler clothing. (wolf in sheep’s clothing)

    The crux of the problem is when we try to overcome some basic laws of nature in trying to push the monohull form pass its ‘hull speed’ in an efficient manner, whether power or sail. Sorry, but it just takes more power and some ‘planning surfaces’ to do it. Alternatively we can look at pushing longer slimmer shapes that exhibit less hull speed resistance. In the sail mode we have to space these slimmer hulls apart some considerable distance to get stability to carry the sailplan. In the power mode this wide separation is not required necessarily.

    In the ever-continuing effort to define the term motorsailer, I particularly liked your Supreme Court Justice quote, “We know it when we see it”. I think this is particularly applicable to the increase in both sailing and powering performance available with the multihull planform over that of the monohull. There are still many boaters that are unwilling to accept these very compelling attributes. As you said, “today's motorsailers are evolving quickly, driven by more knowledgeable owners and designers who derive inspiration from the best boats of the past and improve them with modern design technology and a sure eye.”

    Two of the most innovative monohull vessels I’ve seen that take efficient cruising into mind along with increased performance would have to be Chuck Paine's Steadysailer <>
    and Steve Dashew’s FPB (fast pilot boat) series <>
    Dashew’s vessel is not a motor sailer as it has no rig, but it is an honest attempt at efficient cruising under power. Here also in the strictly power category the multihull form will present a formidable challenge to the monohull form….just look at the variety of power cats already unfolding.

    I believe I have already referred you to my forum posting, “Monohull verses Multihull powersailers / motorsailers”, that starts with a discussion of the Powersailer 20 from New Zealand. Much further along in this subject tread at posting #76 I introduce my observations on the big new MITseaAH
    motor sailer . Within this same tread discussion there is another particular posting you might find interesting, “A Liveaboard Cruiser For The Real World”

    And then I’ve attached another letter I wrote just recently to a gentleman who built a big monohull Rivolta 90 motorsailer
    In brevity I submitted to him, “When I review all of the virtues you sought for your Rivolta 90, I find I can accomplish all of these same virtues in my 65' catamaran design…..And with half the sail area, considerably shorter mast, less engine hp, less complicated keel arrangement, etc, etc. Thus the building cost/selling price of this vessel should be considerable less”.

    Cheers, Brian
  7. yokebutt
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    yokebutt Boatbuilder

    Methinketh perhaps Brians' just a bit of an unprincipled, opportunistic ****, but then again, that's just based on a very cursory and not-very-well-researched impression.

  8. Bob Leask
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    Bob Leask Junior Member

    Dashews Unsailboats

    This might be a little off the topic for a multihull motorsailor forum, but I just checked out Dashews new design at
    and must say that I think it's the most practical real-world cruising boat design I've ever seen. I'm just a little annoyed that it's not my own design, because he has come to so many of the same conclusions I have, for the same reasons, and much the same solutions. The choice between multi and mono for a motorsailer is a matter of tradeoffs as I see it, each would have it's own merits and would be a matter of preference.

    One thing I especially like about the FPB design is the use of two booms for a simple sailing rig (never waiting for swing bridges, no useless windage aloft) and doubling as stabalizer outriggers. Stabalizers, sometimes called paravanes, have much potential for offshore yachting and deserve more attention and development.

    A few sailors have used them offshore and loved them. By using only the windward one I'm told that the drag is approximately cancelled out by the increased righting moment, plus the boat heels less and rolls a lot less. When stuck in the heavy seas after a blow with no wind, there were times I would have paid anything to have a set of those aboard. I'm attaching a drawing of a very good type of stabalizer which seems to be unknown outside of the west coast of N America, but has been used successfully on sailboats.

    Attached Files:

  9. brian eiland
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    brian eiland Senior Member

    I don't consider it off-topic at all. I don't consider this just a multihull thread. I like monohull motorsailers as well. I do feel on occassion they have exaggerated some aspects on the monohull craft. Hey, multihulls get oversold as well.

    I just feel the motor sailer concept as a whole has been sorely neglected, and needs some OMMPH added to it.

    I know how long many of us preached the multihull concept in the early days only to combat many naysayers. Well now some of us feel the need to preach the motorsailer concept, and particularly the multihull addition to the concept.

    Yokebuttocks called me an opportunistic ****. Sorry he had to make it personal. I guess I just spent too much time in the past selling the multihull sailing concept, and now feel a need to push the motorsailer, mono or multi.
  10. brian eiland
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    brian eiland Senior Member

  11. Guillermo
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    Guillermo Ingeniero Naval

    I want to thank you for your devotion to motorsailers and your enthousiasm and efforts to widespread the concept. I have been following you since some years ago, as I'm the commodore of the Banjer 37 Motorsailer Club and keep a site at, where we also talk about motorsailers and some links to your pages have been added.
    Keep on doing the good work.
    Best regards.
    Guillermo Gefaell
  12. Bob Leask
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    Bob Leask Junior Member

    I considered a reply to Yokebuttocks (his handle says it all) but like his ilk in the amateur radio world the worst thing you can do is acknowledge their presence. I don't doubt he's wanking off on the 2 meter band when he's not here. I do like this forum and appreciate the time you've put into it.

    I'm still favouring a catamaran as my ideal boat because I feel a multi beats any mono as a liveaboard. However if I ever got the urge to go wandering around the world again I would probably choose something like Dashews Unsailboat. Dashews design would be a good choice if you planned to do a lot of miles offshore, and wanted to visit places where moorage is scarce. On the other hand for off the beaten path places where beam is not a problem, the cat is the hands down winner.

    Some of the qualities I admire in Dashews design which are usually lacking in modern designs are:

    flush decks for high structural integrity, a well thought out plan for handling and storing the dinghy (very important), all around unobstructed visibility from the deckhouse, consideration of the seakeeping qualities of the boat, as opposed the the speed-is-everything monomania of most contemporary yacht designers, shallow draft, designing for efficiency at a modest speed as opposed to throw-in-a-bigger-engine

    About the only thing missing is a hard canopy over the aft deck. One of the nicest things about motoryachts is that shady aft deck where you can put tables and chairs and sleep there in the tropics when it's too hot to be inside. I always liked mooching a cold beer from people on motoryachts when it was 50 degrees C down below in my keelboat.
  13. brian eiland
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    brian eiland Senior Member

    Beautiful Monohull Motor Sailor

    I've had this one stored on my computer for some time now. She is a beauty

    Custom, 52’, pilothouse, twin engine, auxiliary cruising sloop with clipper bow, counter stern, round bilge and full ballast keel with slot for drop keel designed to be lovely and functional. She has best of everything and sails in a manner one would expect of such lovely yacht.

    LOA" 51'6" Beam: 13'5" Displacement: 41,000 lbs
    Draft: 5'2" / 9'3"
    Engine(s): Volvo Engine(s) HP: 60 Engine Model: MD30A
    Cruising Speed: 7.5 kts Max Speed: 9 kts
    Fuel: 250 g Water: 350 g Holding: 55 g

    Below deck, all brightwork is varnished, match grain black walnut. Each locker is fitted with an interior light activated by an automatic door switch. The hanging lockers are lined with aromatic cedar and there are finishing touches such as back-lit etched glass on the china locker doors in the galley and laurel leaf inlays in the saloon and cockpit tables as well as the companionway doors

    Twin Volvo Penta, MD30A, four cylinder 60 hp marine diesel engines with Walters V-drives (2100 hours). Fuel consumption is approximately 2.3 gallons/hour at 2100 rpm (about 7.5 kts). Two blade bronze self-feathering props by MaxProp on 1 3/8” stainless steel shafts with PSS shaft seals. Wagner hydraulic steering from both steering stations to skeg mounted rudder. Robertson AP100DL autopilot with remote controls for operation from the bow or cockpit.

    Sail area: 1250 sq ft. Sails by Doyle (1997): Main, 105% jib, storm jib which sets on a masthead inner stay, and an 1800 sq ft assymetrical spinnaker in a sock. Rigging: Navtec rod rigging with hydraulic vang and backstay. Hood in-the-mast electric furling, PROFURL electric headsail furling. Winches: 2 – Lewmar #40 ST halyard winches on mast, 2 – Lewmar #30 ST winches and 2 – Lewmar #65 ST electric winches mounted on cockpit coaming

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  14. brian eiland
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    brian eiland Senior Member

    Monohull Motorsailer (cont)

    Couldn't resist a few more photos

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  15. sharpii2
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    sharpii2 Senior Member

    Hi everybody.

    How about this for an idea.

    A design inspired by kayaks.

    30ft length.
    6ft beam.
    5,000lb half load displacement.
    200sft of sail carried on two seperate short masts. (Probably gaff rigged)
    1000lb ballast on a '70s style fin keel with swept back leading edge.
    3hp continuous diesel which would be housed in the center cockpit and would turn a 3 blade feathering propeller.
    100gal deisel tankage.
    5kt cruising speed goal.
    A permanate awning over the center cockpit.
    Permanate sleeping for two in the aft cabin and makeshift sleeping for two guests in either the forward cabin or the 7ft long cockpit (depending on the weather).

    Who says motor sailers have to be big, bulky, and expensive?

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