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

    I've wanted to bring up a subject that seems to be a trend amoung monohull folks lately. I can only think it has to do with the competition they are feeling from the multihull market. I continue to see these inflated claims as to their particular design's performance capabilities, particularly under sail.

    Case in point. Have a look at the new PowerSailer from NZ.

    Can you really believe that a 28 tonne (I would venture to guess heavier by the time its finished) monohull vessel will 'sail' at 18knts??...even with a 110' mast. The vessel is only 66' long and carries a 21' beam. And I imagine it will be very difficult to keep that underwater, retractable Z-drive housing/sea chest volumn free of sea water (lots more weight). And she's carrying around a 13.6 keel and twin rudders. Granted the small print says in a downwind surfing condition, but they advertise the vessel as though a perspective client should readily expect such performance....wishful thinking I believe.

    I've seen some number of other monohull manufactures claiming some 'very optimistic' speeds for their sailing performance lately....can't recall the specifics at the moment, maybe someone else can fill in the blanks.

    Now, to get to 'planing speeds' desired of this power sailer she's going to need 800hp....boy, that's not going to be light. Then how do you get the rt-angle gears of a Z-pod unit to stand up to a continuous hp rating of this magnitude??

    Plus they're going to have a retractable keel (more weight) to gain entrance into shallow areas. And the vessel is going to be unsinkable??

    It seems to me they should just accept the multihull motorsailer planform in the first place, as all of these goals (and their others) are met with this planform.

    Boy, I wish I could find a boater such as this gentleman, who would wish to put the money and effort he has committed into a custom catamaran motorsailer design. We could accomplish this sort of performance with a 75' mast, two 200hp engines, and a 3.5' draft.....probably cheaper too.
     
  2. Ilan Voyager
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    Ilan Voyager Senior Member

    Impossible ciphers


    I agree totally with you. I'm fed up of all these impossible claims and "over technology" I see in too many internet sites. Any naval engineer or architect with some experience would laugh of such claims.

    And as you said a cheaper, simpler and safer alternative is a catamaran.
     
  3. brian eiland
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    brian eiland Senior Member

    Motorsailers

    Yacht Design Competition
    Boating International & Camper/Nicholsons
    (“the best boat to undertake a world cruise”)
    (cover ltr)

    Well here’s my submission, a Motor/Sailer.

    I was a little disappointed that you didn’t have a separate category for this combination of sail & power, rather than just lumping it in with the sail category....but that seems the way the motorsailer has been treated (neglected) for so long. I tried to get an article on motorsailers into the current very popular American magazine, “Passagemaker”,......no way, the boat has sails on it!...... As though the only true passagemakers were trawlers.

    I asked my friends at the Annapolis Boat Shows (were I had participated for years) about bringing in a display model of my gamefishing cat to the PowerBoat Show.....no way, it has sails on it!

    I ran into the same situation when I tried to get my motorsailing/gamefishing catamaran design published.....not in the gamefishing mags as this boat has sails on it.....and not in the sailing mags as this boat has a fishing chair and big engines in it.

    So I’ve not been able to get this motorsailing design published.....only a 30-year-old article on the sail-plan idea itself. Hopefully I will be considered as unpublished in your definition, as I have not had this design published in any printed publication I’ve had to resort to taking some computer courses, and finally getting a website up to promote this idea. I feel like I’m in the same ‘uphill’ battle with the marketplace that I was for18 years in the sailboat business pushing ‘the multihull concept’. Several times I’ve put this idea into hibernation, particularly the ‘Gamefishing Under Sail’ idea. My comment at the time was something like, “I just spent 18 years in the sailboat business trying to convince sailors of the virtues of multihulls, and now I’m going to try and sell a fishing guy a boat with sails on it. I’ve got to be crazy!”

    So now you are the happy recipient of this idea. I hope you take a little time to give this concept some serious consideration as a great vessel concept ‘to cruise the world ’. In the essay I submitted I had to spend quite a few of my allotted words to talk about the motorsailer concept in general, rather than my design in particular. It wasn’t as though I could just say trawler and all would be assumed as understood. The word motorsailer (or motorsailor or.......) just doesn’t translate that easily.

    You encouraged innovative ideas. I think I’ve presented a few, and particularly my sail plan. I chose not to expound on the performance potentials of this unique rig, but rather just point out those particular features so applicable to the cruising situation. And those would exist regardless of its potential windward capabilities with tight, straight forestays.

    While I have your attention let me bring up another of my observations about cruising sailboats I made long ago. I always felt that the raised saloon/deckhouse arrangement was a particularly good one.... up where you can see the world around you rather than buried down below. Look at the multitude of today’s monohull designs that are incorporating this raised saloon concept, maybe due to the popularity of the catamaran configuration.….and/or some number of the early motorsailers that incorporated this feature. My twin keel monohull incorporated a mini version of this feature, and was introduced back in the early days when there were VERY few cruising specific designs, and the Out-Island series was just coming on (something like 35 years ago).

    If I were choosing a monohull vessel as a world cruiser, I would give serious consideration to a vessel such as my twin-keeled monohull perhaps extended to 60-65 feet, with an expanded upper saloon/cockpit, and only two big staterooms at either end. With a good size engine, my ‘ketch’ sailplan, and shallow draft/directional stability of the twin keels it would make an excellent motorsailer.
    ________________________________
    Yacht Design Competition, Contest Essay
    (“the best boat to undertake a world cruise”)

    I sincerely believe that a well conceived Motor/Sailer is the most practical, capable, comfortable, economical vessel for serious ocean passagemaking......and retaining the ability to explore the most remote coastal areas.

    Even Beebe’s book,”Voyaging Under Power”, the bible of the power-only crowd, his vessel, “Passagemaker”, was a motorsailer, albeit smaller rigged than he really wanted. Many of the examples he offers as prime passagemakers are instead prime coastal cruisers, ‘semi-displacement’ hulls not optimized for long passages, but rather coastal cruising, where rapid transit is a primary requirement, while fuel use and surviving ultimate conditions are secondary considerations. ‘Trawlers’ today are gravitating toward planning hull configurations, and twin engines, as buyers become reluctant to accept slow 7-9 knot vessels. And forget wide appeal of primarily sail-powered vessels, particularly with our aging population.

    We don’t hear much of motorsailers these days....not a popular subject. The old traditional, stoutly-built vessels, with a hefty engine(s), were necessarily compromised in both their sailing and powering statistics. Let’s modernize the motorsailer. The multihull planform holds great promise to improve this breed. The long slender hulls of the catamaran vessel have proven real efficient to push under both power & sail.....not only efficient, but not limited to the traditional slow displacement/length hull-speeds. Just what the motorsailer needs....far less compromising increases in both sail and power performance, while maintaining economy of operation that truly allows long-range capability.

    Let’s explore a 40' example. Take the single 120-140 hp diesel used to push the conventional 40' single-hulled trawler or motorsailer to a maximum 8.3 knots hull speed and divide it into two smaller 60 hp diesels driving two long slender catamaran hulls. Voila!, maximum to 15 knots under power with the reliability of twin engines and the stability of a twin-hulled vessel. Add a modest sailing rig to these easily driven hulls, and you now have a passagemaker capable of cruising 12 knots under sail/ power compared with those older 7-knot boats. With 12 knots of speed at your command, you can really take advantage of 'weather windows' to; 1) make your passage as smooth as possible, 2) make some lengthy passages you might never have considered in a slower boat. This multihulled vessel will likely be slowed less by an obstructive seaway, and will accordingly make a passage at almost twice the average speed of the single-hulled vessel...twice the speed for the same total HP. There is an economy of operation here that cuts fuel requirements and bills, and greatly extends their range. In light airs, running one engine often is all that is needed to bring the apparent wind forward to make the sails work harder, and the combination provides much better results than either motoring or sailing alone……
    .sailing synergy/harmony, the motor taking over in the lulls and the rig taking over in the puffs.

    The sea-kindliness of multihull craft is being rediscovered every day. Continual experiences with whale watching boats, fast ferries, pleasure, commercial, and military applications are all proving the validity of the multihull form. What many people forget about a good ride in a heavy sea is that it is very much a function of weight in addition to hull shape. More weight, more robust, more form resistance it offers to moving thru the ocean, the more the sea acts to resist the vessel's progress, and thus the more uncomfortable ride, and we must slow down. A big headsea is a particular challenge. Heavy boats carry their momentum into each trough and crest in a battle with the sea, while lighter weight vessels with slender hulls slice through with less battering. Per a sign at the Naval academy, “you can out-think the ocean, but you can’t out-slug the ocean.” Modern materials allow for lighter boats, and we must properly distribute the vessel's weight throughout long slender hulls. Following seas tend to pick up broad sterns and slew a vessel off to either side....broach. The catamaran hull does not require these broad stern shapes.

    Storm survivability should be considered at the design stage for any vessel making offshore passages. Loss of power (clogged filters, etc) often occurs at the most inopportune time (during a storm), and this can put the solely powered vessel at peril in short order. A vessel with a modest sailing rig could save your life, and the vessel’s. Add a proper sea anchor installation, and I would challenge a hurricane. The catamaran planform rated ‘best in survivability’ in huge breaking wave tests* carried out by Lock Crowther at the prestigious Univ of Southampton.

    Most innovative item on my vessel, the mast-aft sailing rig, also referred to as a ‘single-masted ketch’....a marriage between a cutter and a ketch without the mainsail. I have LOTS of data to support my contentions as to the aerodynamic superiority of this configuration.... But lets leave that theory out of the equation for our motorsailing application. The ketch rig is a good small-crew size rig, particularly where all three sails are roller furling!....even a novice could learn to operate this rig.....and she balances under a variety of sail deployments. Lower force centers add safety. Boats with moderate rig proportions tend to make faster overall passages because they are sailed at a higher level of efficiency than if they carry a lofty hi-performance rig. No big head-bashing booms, and just wing/wing the headsails downwind. The sail rig contributes damping action to the rolling in a beam/quarter sea (no servo-fins needed), contributes to an unlimited range, and ultimately it will get you home if the engines fail. Ahhhh motorsailing!

    Optional nacelle-mounted centerboard precludes any extra hull penetrations, and permits maintenance without hauling-out. ‘Pointed’ deckhouse shape conforms to apparent winds, significantly reducing drag. Flying bridge & crows nest. Dedicated engine rooms, isolated from living spaces. Copper-nickel hull material below waterline is impact resistant and naturally antifouling for years.

    Accomodations!! How might it appear as a real estate ad?, “Waterfront cottage, 4/5 bedrooms, three baths, large kitchen & dining area, big deck, wonderful views.” Hard to beat a catamaran’s spaciousness and privacy....witness their current popularity in the market. Seamanlike layout... no vast open spaces.

    My 65' Motor/Sailing catamaran is the embodiment of a Phil Rhodes’ motorsailer design that has haunted me all these years. Only, this vessel is so much superior. Twin 100hp diesels will cruise her at 12/14knts. Under sail she could make 18/20kts. Range, unlimited. Fuel consumption, extremely low. She could skim over depths as little as 3.5'. Explore those rivers, mangroves, coves, lagoons. Beach the bows. Dive or fish the flats and the reefs from the Bahamas to the Pacific atolls. THIS IS AN EXPEDITION PASSAGEMAKER!! 20-25meters, no crew required.


    * reference source: (Lock Crowther Designs Catalogue 1980)

    “This work has indicated that the well designed catamaran is remarkably safe in breaking waves up to considerable height, even when beam on, we were unable to capsize a power catamaran yacht in the largest wave which could be generated. This corresponded to a 52' wave for a catamaran of 40' beam. Scaling this down to a typical 24' beam cruising cat means she should be O.K. in a 31' breaking beam sea. An equivalent size mono-hull power boat was easily capsized by a 25' breaking sea, and in tests with conventional yachts after the Fastnet disaster, it was found that a 40' mono-hull yacht could be capsized in a 12' breaking sea.”
     
  4. sharpii2
    Joined: May 2004
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    sharpii2 Senior Member

    motor sailer catamaran

    Dear Brian:

    I first want to ask you a few questinons about your design concept. then I want to make a few humble suggestions. First the questions. For the sake arguement, let's stick with the fourty foot version. It can be afforded by your average millionare.

    First question. What would its waterline length be? 36ft? 40ft?

    Second question. What would its displacement be? 5 tons? 10 tons? 20 tons?
    My guess is 10 tons. Am I right?

    Third question. What would be its centerline to centerline beam. My guess is 20ft. Am I right?

    Fourth question. What would be the wl beam of each hull 5ft? 6ft? 7ft?. My guess is around 6ft. Am I right?

    Fith question. How far along the over all length would the wing deck extend. 35%? 50%? 75%? My guess is at least 75%. Am I right?

    Final question. Would there be standing headroom in the entire cabin or just in the hulls and the pilot house?

    Now for my suggestions.

    First. Why not just make it a cutter? Its a rig that has most of the advantages you are looking for, doesn't look bizzare or ugly, and, most important, won't scare potential clients away.

    And second. Why not submit a simple profile drawing along with vital stats to a magazine that is a bit off the beaten path such as "National Fisherman", "Boatbuilder" or even "Passagemaker"?

    Best wishes. Bob
     
  5. fcfc

    fcfc Guest

    Why dont multihull guys give curves or figures like:

    http://www.nordhavn.com/40/overview.htm
    or
    http://www.kadeykrogen.com/krogen44speedandrange.htm
    or
    http://www.beneteaupower.com/swift/performance.php

    And why malcolm tennant in this page
    http://www.tennantdesign.co.nz/news.php?story=33
    graph : http://www.tennantdesign.co.nz/uploadImages/big1097718450fuelcompmono.jpg

    does compare with a monohull who is the shortest and heaviest boat of the tested boats.

    Why does not he uses :http://www.classic-boats.com/gamme/fotos-boats/and15-ecran1.jpg or http://www.rodgersyachtsales.com/and.html
    who is lighter and longer and does 20 kts with 2* 150 hp ?

    The graph scale also are a bit strange. comsuption per displacement without any unit. Why not simply use GPH ?

    Another point for power multihull : the average buyer will burn fuel 50-100 hours only per year but will pay marina fees all year long (even with no use).
     
  6. yipster
    Joined: Oct 2002
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    yipster designer

    there is some info...
    [​IMG]
    on the 15 meter veridian diesel electric i read forexample:
    more info on request i guess...

    i do belive malcolm tennant is one of the experts on power cats and enjoyed reading his good maritime articles again...

    propulsion,
    displacement powercats
    development in hulls
     
  7. fcfc

    fcfc Guest

    About the veridian, it uses full power for 28 kts, so 2* 350 = 700 hp.

    And only 22 kts, it burns 50.6 liter per hours. this translate in rougthly 250 hp.

    Need to nearly triple the power to gain about 27% in speed.

    For me, it is strange, since I dont forecast any flow difference for the hulls between 22 and 28 kts.

    If I translate to monohull, 125 hp would drive a 9 t very slender 52 ft hull to 22 kts. But it would need 300 hp to drive a 11 t 50 ft monohull 11.5 ft beam to 20 kts. see http://www.rodgersyachtsales.com/and.html

    Even Ilan voyager need 140 hp to do 21.5 kts, but it is longer (70 ft) , and I suspect it is really lighter. From N Irens site "The 1568 mile trip was completed in 72 hours at an average of 21.5 knots and required just 2000 litres of fuel." 2000/72 = 27.7 l /h or about 138.8 hp
    (From popularmechanics, Ilan voyager should be about 11000 lbs = about 5 T
    yanmar endeavour is 5000 lbs = 2T2.)


    Unless it is 50.6 l/h *PER* engine.

    In that case , we would have 700 hp for 28 kts, 500 hp for 22 kts. 40 % increase in power gives you 27 % increase in speed.
    And the 9 t demihull would require 250 hp to go to 22 kts, more or less in par with the 300 hp needed to drive a less slender 11 T hull to 20 kts.

    But that would be an enormous mistake from Malcom Tennant.
     
  8. fcfc

    fcfc Guest

    For efficiency, I am going to think (powerboats) :

    1) the longest waterline possible.
    2) the lightest possible.

    The remainder is ****.
    monohull, catamaran, trimaran, xxxxmaran , slender is worthless from an efficiency point of view.

    Now for a given length and building technology, the ligthest boat is the narrower one by ordinary physical constraints. And you need some stability if you want your boat usable.

    That s all.
     
  9. fcfc

    fcfc Guest

    Funny I dont see my previous post ...

    About the veridian, it uses full power for 28 kts, so 2* 350 = 700 hp.

    And only 22 kts, it burns 50.6 liter per hours. this translate in rougthly 250 hp.

    Need to nearly triple the power to gain about 27% in speed.

    For me, it is strange, since I dont forecast any flow difference for the hulls between 22 and 28 kts.

    If I translate to monohull, 125 hp would drive a 9 t very slender 52 ft hull to 22 kts. But it would need 300 hp to drive a 11 t 50 ft monohull 11.5 ft beam to 20 kts. see http://www.rodgersyachtsales.com/and.html

    Even Ilan voyager need 140 hp to do 21.5 kts, but it is longer (70 ft) , and I suspect it is really lighter. From N Irens site "The 1568 mile trip was completed in 72 hours at an average of 21.5 knots and required just 2000 litres of fuel." 2000/72 = 27.7 l /h or about 138.8 hp
    (From popularmechanics, Ilan voyager should be about 11000 lbs = about 5 T
    yanmar endeavour is 5000 lbs = 2T2.)


    Unless it is 50.6 l/h *PER* engine.

    In that case , we would have 700 hp for 28 kts, 500 hp for 22 kts. 40 % increase in power gives you 27 % increase in speed.
    And the 9 t demihull would require 250 hp to go to 22 kts, more or less in par with the 300 hp needed to drive a less slender 11 T hull to 20 kts.

    But that would be an enormous mistake from Malcom Tennant.
     
  10. Ilan Voyager
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    Ilan Voyager Senior Member

    fcfc, Ilan Voyager is heavier than five tons. A good 60 race tri, all carbon nomex has a true weight of about 5.5 to 6 tons ready to sail; claims of far lower weights are originated by the use of illegal substances or incurable optimism.

    Ilan is made in a low tech strip plank and glass (no carbon) with confortable scantlings. The boat has now almost 20 years and is in perfect condition (used everyday as small ferry in Cabo Verde islands in strong seas). I do not know the displacement of Ilan Voyager but some rough calculations give a weight fully loaded of a range between 8.5 to 10 metric tons. The best is to ask with european politeness to Nigel Irens who is a very kind and well educated person...

    Yanmar Endeavour is made of lighter composite and I think it was handicapped by the diesel outboards (but Yanmar was a main sponsor...). A single diesel with a "big" slow turning propeller would have a better efficiency. The weigth of 2.2 tons is an empty weight. The formula 40 (totally empty race boats) weighted in 1987 at the Grand Prix de Brest from 1755 kg (and needed 45 kg of ballast to get the minimal weight of 1800 kg) for Data General to 2560 kg for the Beneteau built cat used by Randy Smith. Ciphers given by memory.

    I agree with you for some of the other assertions: weigth is the enemy. But from the studies made by the english, australian and french the best configuration for 20-30 knots range speed is the trimaran. At least 20% better efficiency for the same lenght/same weight. I agree with you that Ilan was using an average power of 140 HP during the round trip of England, but think the boast was 2000l*0.85= 1700 kg lighter at the arrival. I have to add that most part of the trip has been made in not very gentle seas as the North Sea, and the scottish coast are not known for their soft conditions.

    We can make a guess: 140 HP are required for a 7 tons (reasonnably optimistic estimation, I think the empty weight is heavier) empty boat plus 850 kg of fuel, so a total weight around 8 metric tons to get 21.5 knots. That´s very good in open sea.

    Studies have been made very seriously as the english one has been founded by the Brittish navy with a very intensive towing tank campaign involving a top cream staff. And the results were good enough to put the money for building the RV Triton, when you know the tight budget and the conservatism of the Brittish Navy... It seems (difficult to get reliable infos while military are involved...) that the theoretical studies are confirmed by the sea trials.

    Australian are studying trimaran fast cargos, and the Russians believe strongly in the trimaran formula, but they are more than short of money.

    Military navies have comparison means as a lot of warships can be ranged in the slim boats (ratio LWL/BWL > 6) working under hull speed and their design is perfectly known. You can imagine that a navy will not spend a fraction of billion dollars on a boat without making a serious study and good campaign of towing tank trials...
     
  11. brian eiland
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    brian eiland Senior Member

    RV Triton and US Navy spending

    I thought the Triton project turned out well and that the US Navy would go the next step in development. I have not followed Navy projects for a long time, so I'm not sure where they are with additional studies. I suspect they are NOT proceeding with it as it wasn't technogy developed here. Instead they will spend billions on developing alternatives that may make no sense at all.

    As to our Navy not spending monies on projects without making at minimum some 'serious studies' of them in advance, well have a look at this M-Hull project

    M-Hull project
     
  12. Ilan Voyager
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    Ilan Voyager Senior Member

    Mr Eiland, you seem very ironic...-smile-

    In fact the M hull project has nothing to compare with the Triton project.

    On the english side, you have after theoretical studies made at a university, an expensive towing campaign and the construction of a 90m ship, plus the cost of a 2 years of trials plus further brain work. All that to imagine the next generation of frigates. That involves a long term policy and big financial risks. I'm afraid for the brittish, that the principal defect of the Triton is being english... and the US Navy is more than conservative. It will be the same fate for the power catamaran project as the design is australian (Incat).

    All the major navies share this characteristic: no use of foreign designs. If you add the prevalent policy of the White House, the use of a foreign design (even from theoretical allies but the british policy may change in a close futur and the australian are now more bonded to the asiatic countries than to the brittish) becomes very unlikely.

    On the other side, you have a 6 million bucks (that is nothing in the US navy budget) contract between the US Navy and a private company for a small boat. Curiously the company is presided by a former Secretary.

    It's pure guessing but that smells simple sugaring, and confortables wages for improving the incomes of the former secretary. After building (you do not need 6 M US$ for a small proto unless the workers are paid 250 US$/hour and you're paying 100 US$/pound the aluminium) the boat will be evaluated and maybe (I hope so for Mr Burns, who I think he believes totally in his project) there will be another contract. It's saddly probable that the boat will finish in a junkyard at San Diego or Norfolk after a few trials, as a lot of other boats. Simply because in the past, none boat with the "gull wing" configuration and/or air cushion have worked well enough to remplace the classic boats, and only God may know how many have been tried.

    Neverless is a good way to get new designs at low cost, and it's an old policy in the US Navy which gave good results in the past.
     
  13. FAST FRED
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    FAST FRED Senior Member

    "The sea-kindliness of multihull craft (CATAMARANS)is being rediscovered every day."

    No problem , but a real offshore boat needs Stability ,

    NOT CATAMARAN "stability" which is as good upright as inverted.

    Knock downs are inded rare in motor boats , but at under 100 ft not particularly hard to do. At only 40 ft, dont run many inlets , in 40k of breeze.

    Multihulling since 1966.

    FAST FRED
     
  14. Ilan Voyager
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    Ilan Voyager Senior Member

    Fast Fred, only monohull sail boats and some special power boats are able to upright themselves after a capsizing if they do not sink being filled by water.
    The majority of boats are not able to right up without exterior help. I would add that is a same for a majority of objects as cars, bycicles, motorcycles and others.

    If the monohull sail boats have the possibility of self righting, they sink very easily because of the ballast as I almost experimented myself twice: a knocked down monohull sailboat stays half filled of water across the wind and the waves are passing over you...a very unpleasant situation. Do not hope that a power monohull is able to self righting while the superstructure is filled of water rushing by the doors and broken windows.

    While being officer in the navy, we have had to rescue too many inverted power monohulls, mainly small yachts anf fishing boats. A good cat or tri is very hard to capsize, with modern meteo you can stay away as far as possible of big storms, so the event of capsizing becomes unlikely on cruising boats. Life is a inverted multihull is far easier and less miserable than in a rubber lifeboat...

    The price to pay for a self righting boat is high: heeling, rolling and loss of efficiency as you have a ballast which costs a lot of energy to move. These inconvenients are present 99.999999999999% of the time....
     

  15. 249

    249 Guest

    I once worked out that I've known about 6 people who have capsized multis offshore; two were racing internationally, one was an extremely experienced cruiser, one was a good racer returning from winning (I think) an international event, the other two were on a 380 mile race.

    They spent up to three months drifting around upside-down before being rescued at a significant cost to others (in all but one case). There's also the fact that some cats wouldn't actually float all that well- did you see the pics of the Chris White cat that capsized on the Great Lakes recently? It was very low when it was retrieved, not the best of platforms. Others have broken up while capsized, or capsized due to break-up. They were not good surivival platforms.

    The only case that didn't involve rescue by ships or rescue services involved the guy I knew being picked up by another racer, who died after a capsize in a later multi race. Another guy I knew lost his brother in a capsize.

    This is not knocking multis per se; I advised my mother to get one (she did), I let my 8 year old son go cruising on my brothers', I was recently pestering him to take the boat a few hundred miles out into the Pacific over Christmas.

    Because everyone I've known who has capsized a cat or tri has come back eventually. I've known a couple of guys who didn't get back ever, when their monohulls went down. I've been in a situation where we may have been inches away from a sinking, had the keel and not the rudder hit a sunfish (small and fragile racing boat well offshore at high speed, not particularly strong around the keel) and one of my family's similar boats (lightweight half tonner) sunk in similar circumstances after it was sold. This is not knocking lightweights per se I hasten to add, some of them would take it.

    I've also never been in a situation like Ilan, where a mono stayed knocked down - what sort of boat was that?

    But from one perspective, arguing over whether a sinkable self-righting boat is all that much better than an unsinkable non-righter seems a bit like splitting hairs.

    Isn't either alternative much more dangerous than an unsinkable self-righting boat? Look at some monos with positive buoyancy; the space lost is not really significant in terms of the safety benefit is it?

    Finally, Ilan, maybe not all places in the world have the reliable forecasts you speak of; I've been at inquests were the reliability of the forecast has been a major point of dispute.
     
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