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Power Cat vs. comparable monohull yacht

Discussion in 'General Catamaran Discussion' started by Pelagic Dreams, Nov 26, 2011.

  1. Pelagic Dreams

    Pelagic Dreams Senior Member

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    I have been reading about the benefits of Power Catamaran Yachts in terms of ride stability and better fuel numbers than that of a mono hull yacht of the same length. They seem to have larger deck spaces and comproable luxury amenities as a typical yacht. I don't want to get into a debate of one over the other, what I do want to find out is how the two compare in price?
    Let's say both... fiberglass, twin diesel, 3-4 stateroom en suite...50' to 80'
    I have also noticed that most of the current builders are non-US companies....France and Austrailia are the first to come to mind.
  2. Pelagic Dreams

    Pelagic Dreams Senior Member

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    Two builders I would reference are Sun Reef 70', and the 65' Fountaine Pajot.
  3. YachtForums

    YachtForums Publisher/Admin

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    Neither of these builders would top my list. Matter of fact, both would be at the bottom. The fit, finish and joinery leave a lot to be desired from both builders. Sun Reef is so bad we don't even publish press releases for them anymore. I feel like it would be misleading our readers.

    We have a review upcoming on the Horizon PC-58 Cat which should top your list. It certainly does for me. Horizon got it right, both aesthetically and ergonomically. Richard Ford, who produced an exceptional line of power cats; Afri-Cat, was brought in as a consultant on Horizon's new power catamaran line.

    Economically, the PC-58 might raise a few eyebrows at 2 mil plus, but otherwise, IMHO... a slam dunk. The design and layout is without a doubt the best I've seen in the power-cat segment. Wide open floor plan in the salon/galley with a main deck master and more than adequate guest accommodations, which is something not often associated with guest quarters in a sponson.

    The PC-58 was the busiest boat at FLIBS 2011. We have a sea trial scheduled in early December. The review will go live within 10 days of same.
  4. Pelagic Dreams

    Pelagic Dreams Senior Member

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    Thanks for the Heads up. I am also looking at the Pacific Expedition 60' out of Oregon. Any news on them?
  5. Capt J

    Capt J Senior Member

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    What makes you think that a CAT is the way to go now? They ride absolutely horribly in a beam sea, as well as any other sea that exceeds their center opening height. The only place I've seen them shine would be moderate seas, and they have a lot of deck and main level space. The staterooms are usually very narrow and ackward and most cats have stairs everywhere in them. Get into 4-6's (or more) in most of them and in a head sea, every wave hits the center of the hull and it feels like you're hitting a brick wall. In some area's I could see them as preferable over a mono-hull (powerboats), but not too many.
  6. NYCAP123

    NYCAP123 Senior Member

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    The thing is that cats are real comfortable in moderate seas or at anchor, and have great deckspace. So it depends what you see yourself cruising in or what you want to be prepared for. My biggest drawback is life in a sponson. The on deck master on the bigger cats takes care of that though. That Pacific Expedition 60' Pelagic Dreams mentioned has a real nice looking layout. So like every boat there are compromises and things one boat is better suited for than others.
  7. RVN-BR

    RVN-BR Senior Member

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    Despite my limited experience, I must also point out that you should be aware that any marina you dock at will most probably charge you more than a comparable length monohull because of the beam.
  8. Capt J

    Capt J Senior Member

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    If you can even get a slip. Most marina's might only have a slip or two can accomodate it.
  9. Pelagic Dreams

    Pelagic Dreams Senior Member

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    From what I have read, not many boats love a beam sea. Tacking to a slight head and then a slight following sea seems like an answer to the ride differences of a power catamaran. It increases the course distance but makes the roll better to deal with. Am I "off course" in this philosophy?
  10. Capt J

    Capt J Senior Member

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    VERY. You'd have to attack the waves at, at least a 45 degree angle and in most instances you'd be WAY off course. In a beam sea a Catamaran lurches considerably, like when 2 wheels of your car are on the sidewalk and both wheels fall on the road at the same time. Also the shorter ones, such as the 43' Lagoon at idle/slow speeds going out an inlet with a strong outgoing tide and those rolling waves, they act like a dolphin and ride like one, at faster speeds it's not a problem and on longer cats it might not be a problem either as the boat may span more waves at the same time.

    It looks like I'll be running a 44' Lagoon power cat from WPB to Cancun in the very near future. Hopefully the seas cooperate, as Key West to Cancun is a 345NM non-stop haul. I ran a 43' Lagoon from Corpus Christi, TX to Fort Lauderdale, FL so I have a fair amount of miles on a cat, as well as having done short hops on a few others.

    As for fuel burn, if I remember correctly the 43' Lagoon burned 1.5 GPM at it's 17.5 knot cruise. We averaged 1.1 NMPG on the trip from TX to Ft. Laud.
  11. Pelagic Dreams

    Pelagic Dreams Senior Member

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    Capt J, thanks for the insight. From someone who has actually ran a cat I can heed your knowledge. We are looking at a cat in the 60' range. With that said, we are going to cruise at 6 months at a time with no time table to force us from one point to another. We can pick our weather as we will.
    As we speak, our boat of choice is a LRC Trawler such as the Bering 21m steel hull. My interest in Cats is due to its MPG and it stable roll platform. Living on a yacht for extended periods the "out doors" becomes very important and the Cats seem to have an abundance of wide spacious decks.
    We like the ability to passage at the 10knt speed, but if you have to out run weather....being able to get up to 17-20 knts. would be nice.
    We have not made up our mind, we are looking into all the possibilities for our future purchase.
  12. brian eiland

    brian eiland Senior Member

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    Domino 62 PowerCat

    Just as Capt J seems very negatively inclined to accept multihull vessels, I'm the opposite...very positively inclined to promote their virtues

    I would suggest you have a look thru this subject thread that occurred recently on this forum.
    http://www.yachtforums.com/forums/general-yachting-discussion/16781-expenses-cruising-budget-examples.html

    I would further recommend that you visit the extense blog that they have been posting from the building of this vessel down in South America thru their cruise up thru the Caribbean and then up the East Coast of USA this past summer, then down to Central America....certainly a LOT more sea miles in a powercat than many others.

    I can lead you to a few other such lengthy trips in power cats including a number od Ocean Crossings.
  13. u4ea32

    u4ea32 New Member

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    Dont get fooled by comparing apples to oranges!

    The wonderful MPG attributed to cats is due to comparing apples to oranges. When comparing a heavy monohull to a light multihull, sure there are advantages. But comparing a light monohull to a heavy monohull will actually result in better MPG.

    Be aware that MPG is linearly related to displacement for a given hull form and speed. If you compare a heavy sportfisherman to a light one, the MPG basically varies by the displacement: one that weighs half as much as the other gets twice the MPG.

    In general, multihulls are built lighter because their performance and seaworthiness degrades dramatically and quickly with increasing displacement. As mentioned above, a heavy cat results in a low wing deck (aka bridge deck, the connection between the two hulls) and a low wing deck results in horrible slamming: uncomfortable, but also very bad for the structure of a boat.

    A key source of confusion is the clear evidence in the sailing world that the fastest sailboats are certainly multihulls, and in particular, catamarans. However, sailboat speed is primarily driven by weight and stability. By eliminating lead ballast, one gets rid of 50% of the weight. By using the righting moment due to bouyancy rather than displacement, its a winning formula.

    But even then, sailing multihulls only outperform sailing monohulls of similar displacement and stability once flying a hull. That's because two hulls (or three) going through the water require much more energy than one for the same displacement. More energy is required for two reasons: 1) more wetted surface, and 2) far more wave drag because the waves of the two hulls combine instead of cancel. Trying to squeeze incompressible water between two hulls takes a lot of energy!


    Here is a simple experiment if you've got a row boat or kayak or canoe: get going any comfortable speed in deep water. Then, go over some shallow water, say a foot deep. You will feel quite clearly that you slow down a lot, and it takes a lot more effort to try to even approach your original speed. This is the reason that ship speed trials are ALWAYS performed in deep water.

    Now, once a sailing multihull is sailing on the one hull far to leeward, speed increases dramatically. But of course, now you effectively have a very thin monohull, not a multihull!

    If you really want to achieve high efficiency as promised by power cat vendors, you really want 1) light, 2) long, 3) narrow, and 4) a single hull!
  14. Pelagic Dreams

    Pelagic Dreams Senior Member

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    very interesting....has anyone done a test comparing a cat with a mono hull of the same displacement? Pound for pound, same gross tonnage, how do the figures compare.
    This is a big factor since doing my research I have really found the living "platform" of the power cat very impressive....but fuel does make the world go round.....as they say.
  15. brian eiland

    brian eiland Senior Member

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    I would suggest you go review some basic displacement/hull-speed theory in vessel design. You are way off base.
  16. brian eiland

    brian eiland Senior Member

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    You might have a look at this 62' powercat belonging to a good friend of mine (not for sale). I recommended this type of vessel back over on this other subject thread....for various reasons.

    http://www.yachtforums.com/forums/123583-post41.html

    ...and have a look at his 'custom cat dinghy'

    I'll get you some real time fuel milage figures shortly...I think you will find them quite pleasing ;)
  17. u4ea32

    u4ea32 New Member

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    Would be interesting to know the error. Please share.
  18. brian eiland

    brian eiland Senior Member

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    Wave making resistance - Wikipedia, the free encyclopedia

    http://www.multihulldesigns.com/pdf/powercatslt.pdf

    http://www.oossanen.nl/download/perryvanoossanen_-_motor_yacht_hull_form_design.pdf

    Here are just a few reference discussions that came up with goggle. I'm sure you can find many more on this very subject.

    In general if you keep the slenderness ratio of those hulls above 8 to 1 your displacement (wave making) drag is seriously diminished
  19. Marmot

    Marmot Senior Member

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