Reasons to stay "Monohull"

[Sandero]

Frankly I would think for most sailors contemplating a new boat the general statistics of derived from anecdotal evidence likely does not inform their decisions on whether to change from mono to multi.

This thread like so many on CF veers off course into largely irrelevant minutia pretty much unrelated to the OP.

Posts have identified all the key factors which inform one's purchase. It appears that those who stick with the monohull are not motivated by the supposed advantages of multis... a stable platform and significantly more real estate for the same LOA.

[Sandero]

Originally Posted by Dockhead

I think most of this is very sensible, and an interesting analysis.


I must, however, object to the comparison between a 38 foot mono and a 38 foot cat. No one chooses between a 38 foot mono, and the far greater volume 38 foot cat! It is silly to talk about "cats are expensive", fallaciously comparing them foot for foot. You don't compare houses based on the width of the facade, do you? You talk about area. These cat mono comparisons are like saying, wow, this 75' wide house is so much more expensive than that 75' wide house, how surprising! Well, not at all if you consider that one of them is twice as deep and therefore has twice the floor area.

So someone trying to choose between a cat and a mono will be comparing a 38 foot cat with probably a 47 foot or so mono, and they will find the cost is similar for a similar amount of hull volume and for similar build quality.

But this feeds back into Pollux's correct analysis of safety -- comparing like for like, that is $ for $, or hull volume for hull volume, and definitely NOT length for length, it is indeed easier to achieve a given level of safety in a mono.

And that's probably why serious long distance voyaging is done almost exclusively in monos, or in really large cats of say 50' or more.

But for ordinary cruising, in anything other than small boats (not Category A), I agree with Polux that there isn't any significant difference in safety between cats and monos. If there were, you would see it in insurance rates, but you don't.

This is a sensible parsing of the size issue. However I wonder if equal volumes of a mono and a cat cost the same. From the little I see of multis they are very "plastic" and the monos interiors are more like living within a piece of furniture. Of course some of these modernist monos do have the "Ikea" look or if you prefer.. Italian modern.

Someone who is thinking about their next boat... probably would think that the move from a 40' mono to a 40' cat gives them lots more space, same sail area more of less compared to a new mono say 45'. This is really comparing apples and oranges... both fruit but taste different.

[Lizzy Belle]

Originally Posted by Sandero

This thread like so many on CF veers off course into largely irrelevant minutia pretty much unrelated to the OP.

Which happens a lot on CF - usually the same people posting the same discussion over and over and over ...

[arsenelupiga]

Originally Posted by Sandero

Frankly I would think for most sailors contemplating a new boat the general statistics of derived from anecdotal evidence likely does not inform their decisions on whether to change from mono to multi.

This thread like so many on CF veers off course into largely irrelevant minutia pretty much unrelated to the OP.

Posts have identified all the key factors which inform one's purchase. It appears that those who stick with the monohull are not motivated by the supposed advantages of multis... a stable platform and significantly more real estate for the same LOA.

i have absolutely no intention of influencing you.

However, as many other cat owners are pissed by misleading/false/abusive conclusions about cats on this forum. Presume to increase traffic.

And yes, monos are not perfect as we can see. Many own Fantasy XX mono.

[sailorboy1]

I don't feel a lot of this cat "volume" thing matters. It's like a large living room where the extra space is mostly empty. The only time it would be of use is when you have a bunch of people standing around in it.

[Polux]

Originally Posted by Dockhead

...

I must, however, object to the comparison between a 38 foot mono and a 38 foot cat. No one chooses between a 38 foot mono, and the far greater volume 38 foot cat! It is silly to talk about "cats are expensive", fallaciously comparing them foot for foot. You don't compare houses based on the width of the facade, do you? You talk about area. These cat mono comparisons are like saying, wow, this 75' wide house is so much more expensive than that 75' wide house, how surprising! Well, not at all if you consider that one of them is twice as deep and therefore has twice the floor area.

So someone trying to choose between a cat and a mono will be comparing a 38 foot cat with probably a 47 foot or so mono, and they will find the cost is similar for a similar amount of hull volume and for similar build quality.
...

Nice to know we agree about most but regarding this I guess you misinterpreted what I meant regarding that comparison and since it happened to you probably I had not been clear, so I will try again.

The point I was making has nothing to do with interior space but with money and seaworthiness.

Regarding monohulls a 38ft boat with a normal stability is considered to have the conditions to be already far away from the size of a monohull that would be considered to have the minimal "acceptable" characteristics to be sailed extensively offshore.

The same happens with a Lagoon 38 that is regarding cats, on a similar position as a 38ft light monohull is regarding the same "acceptable" offshore seaworthiness towards other smaller monohull.

Meaning that a Lagoon 380 is about the same distance of that minimum acceptable stability as it is a 38ft light monohull, both at a reasonable distance, considered for instance that minimum as what NAs as established when they made the RCD regarding class A boats.

Therefore one that wants the same safety margin to sail offshore would have to chose between a 38ft heavy cat or a light 38ft monohull, independent of price or interior space.

If we were talking about interior space we would have to consider a 33ft cat but a 33ft cat is not at the same league as an offshore boat as a 38ft light monohull. In fact there is none that I know off that had passed the minimums to Class A stability requirements (while a 38ft monohull is typically far away from those minimum requirements).

That is why I have said that for the ones that want to sail offshore, if they don't have a lot of money, monohulls are the obvious option and why it makes sense to compare as suitable options to sail offshore a 38ft heavy cat and a 38ft light monohull, in what regards offered seaworthiness.

Note that this notion about what is light varies. For light I am talking about the weight of a typical main mass market cruiser like an Oceanis 38 or a Hanse 385 that weight about the same as a Lagoon 380, being that what is considered light for a monohull is heavy for a cat (of the same size) since these don't have ballast.

[Polux]

Originally Posted by arsenelupiga

like you monos, i follow cat arena for many years so I know about most flips (not extreme racing) . When cat flips, there are often fatalities. Adding up numbers for cruising cats comes around 1/2 people survives, hence 50% survival rate. I would expect keel falling off mono, survival rate at best 50% as cat is designed for flip, mono not for keel loss.

....

4m breker that rolls mono is at least 10x more common than 7m breaker that flips cat over life of boat.

This is how I derived numbers.

If you have better metrics, happy to hear.
....
Flipped cruising cats, less than 10 flips i know of, from 15 years observation.

ok, your turn

You are wrong regarding me as a monohull guy. I look at sailing boats as sailing boats and I like them all. I do follow the cat scene as a part of racing and cruising sailing and the prove is that I can remember more than 10 flips on the last 15 years. Only on the last 5 I can remember more than half of that number and from those several without any live loss, or just one among a crew and it is why I think your 50% is exaggerated regarded fatal causalities.

Regarding the size of a breaking wave needed to capsize a monohull you are considering beam alone as generating stability, ignoring the fact that a cat gets its stability from beam and weight while a monohull gets its stability from beam, ballast (lower CG) and weight and monohulls are heavier length by length than most cats.

Even if regarding the same size monohulls have normally a smaller overall stability the difference is not almost the double as your 4 to 7 meters wave example makes suppose.

And most of all you forget that cats, contrary to monohulls can be capsized by wind alone and many are capsized basically by big gusts, without any significant wave intervention. As you know there are cats that have been capsized at anchor.

[valhalla360]

Originally Posted by Polux

When there are waves there is wind so it makes no sense to talk about being capsized only by waves without wind action.
That was my point. A previous post implied that it was rough waves that flip cats yet I've heard of none.

But I agree that a cat, size by size is harder to capsize due to wave action than a mono but more easier to capsize over a strong gust (monos don't capsize with wind alone). Agreed, but as you indicated big waves typically come with big winds.

Regarding monohulls when rolled surviving rolls they are the vast majority. The ones that sink due to a roll are the small exception.
How do you know how many sink off shore? Generally, there is no evidence other than being reported missing. I suspect (no evidence) that most knock down/rolls do come back up but I also suspect that knock down/rolls are much more common.

Regarding comparative safety I don't think that it makes sense to talk about that, both crafts are relatively safe and I don't believe someone will buy one or another based on that criteria except in what regards some particular cases:

In what regards smaller crafts monohulls are safer and you have an expression of that in what concerns the boats that are approved as category A in what regards passing stability criteria.

A well designed monohull can pass with about 27ft, at 30/33ft almost all monos are approved while cats are only approved around 36Ft and the major brands only start to make cruising cats bigger than that and for obvious reasons while major brands of monohulls start their lines at around 30ft. Actually, there aren't many current cruising cats below 36'. I know at least one that met class A (with minor upgrade package that had nothing to do with the basic design) and a few older models (pre class A standards) that do ocean crossings fairly regularly. Care to list some of the sub 36' models you are thinking of? The ones I can think of are generally not marketed in Europe so they don't concern themselves with the European standards.

A 38ft monohull cost about 70% less than a 38ft cat so for the ones that don't have the money for a bigger cat and can have an offshore boat, monohulls are the obvious answer. Classic flaw in this discussion. A 38' mono is typically equivalent to something in the 30-34' cat. Or vice versa, a 38' cat is equivalent to a mono a little shy of 50' in terms of space. As stated several pages back, I think this is one of the big selling problems for Cats. People who decide they want a 38' boat then see that a 38' cat is much more expensive so they decide cats are more expensive and rule them out before accounting for the differences.

A 38ft feet cat is an offshore safe boat but providing it is an heavy condo cat because if we are talking about really performance cats the size of the cat, to have the same seaworthiness will have to increase and it is not by accident that Lagoon starts its series with a 38ft boat, Fountain Pajot with a 40ft but brands of performance cruisers like Outremer starts with a 45ft cat, Catana with a 42, Le Breton with a 45, Atlantic with a 42. I believe the size is more about meeting market demands. Across the board builders of large cruising boats have thinned their small boat models. I'm talking about cat, mono, power sail...there has been a move to ever larger boats.

Regarding performance cats they imply a awareness and a care regarding sailing that are dispensable in a performance monohull and even more in an heavier cruising monohull. Ignoring the heavy cruiser tag on for the moment, the idea that you can just ignore awareness with a high performance mono is a recipe for death and destruction. If you have a heavy condomaran and sail conservatively, you will likely meet or beat the heavy cruising mono and it will be almost impossible to flip the condomaran. Keep in mind, if you are talking heavy wave & wind action combined, there is typically time get the sails reefed.

Sure one can like and appreciate that, as it was stated by a owner of a fast performance cat, but most cruisers will dispense with that and will prefer a more relaxed kind of sailing and it seems cat sailors too, on a general basis given the vast preference for more stable heavier condo cats.
I agree. The idea of running at double digit speeds is something saved for day sails on the condomarans.

Anyway, boats are what they are and diversity is a good thing as it is a good thing to have sailors with different tastes that allow an incredible variety of sailing and cruising boats.

Perception of cats being expensive is still probably the biggest holdup to larger scale adoption of cats (and the fact it takes 30-40yrs to turn over the cruising fleet). Your comparison of a 38' mono vs a 38' cat is a perfect example. And I'm sure the mono sales people are happy to point it out.

Haul outs and marinas are still a bit of a cost issue as most new boats are not bought by full time cruisers. The people who buy new are rarely the type to leave it anchored out permanently. They have the money for a new boat, they are typically willing to pay for the convenience of a slip. Particularly as you get above 40' finding a travel lift that can handle a 25'+ beam starts to limit your options.

[valhalla360]

Originally Posted by sailorboy1

I don't feel a lot of this cat "volume" thing matters. It's like a large living room where the extra space is mostly empty. The only time it would be of use is when you have a bunch of people standing around in it.

By the same token most people don't need 40-45' mono's space either but that's where the market is going. Again this goes back to comparing "equivalent" boats. If you feel you need the space of a 40' mono, you can look at 32-35' cats to get similar space.

You do reach a lower limit around 30' with cats. Below that it gets really hard to provide much interior room without the design becoming impractical for longer term cruising.

[sailorboy1]

Originally Posted by valhalla360

If you feel you need the space of a 40' mono, you can look at 32-35' cats to get similar space.

Not on the ones I've been on, unless you count the useless empty space.

But unlike so many here it doesn't matter to me what boat someone else wants. I just keep wondering why so much effort goes into justifying it to a forum.

[Dockhead]

Originally Posted by Sandero

This is a sensible parsing of the size issue. However I wonder if equal volumes of a mono and a cat cost the same. From the little I see of multis they are very "plastic" and the monos interiors are more like living within a piece of furniture. Of course some of these modernist monos do have the "Ikea" look or if you prefer.. Italian modern.

Someone who is thinking about their next boat... probably would think that the move from a 40' mono to a 40' cat gives them lots more space, same sail area more of less compared to a new mono say 45'. This is really comparing apples and oranges... both fruit but taste different.

Well, yes. To a certain extent.

But if you were to put yourself in the place of a real buyer, and say to yourself, what can I buy for roughly $700,000 (say), your choices would be a cat of x length, a mass produced mono of y length, or a non-massed produced mono which is a whole different kettle of fish.

Lagoons are made by Group Beneteau, for example, and are built very much in the same way as Benes with the same types of finishes, generally, and equipment. Choosing between a Lagoon cat and and Bene monohull, you really will get roughly the same amount of space for the same amount of money, with similar finishes, just the length of the boats will be different.

As to sailing performance, you will probably do better with the rather longer Bene, compared to the slab-sided condo cat, but the cat will have vastly better performance motoring because of the lack of ballast. And it must be said that if the total space is roughly the same, the way the space is organized of course is very different, with rather smaller sleeping cabins but rather larger salon on the cat (which is a good thing, to my taste).

Yes, they are different fruits, but there are quite a few parallels.

[accomplice]

Now that we're on to comparing size, there are many ways to evaluate and compare relative sizes of boats. Here, it seems most are using interior volume. Depending on the circumstance, LOA, LOD, LengthxBeam, interior volume, gross tonnage, net tonnage (often surrogate for interior volume, but not the same), cruising range under power, number of berths, etc. can be more meaningful measures.

[valhalla360]

Originally Posted by sailorboy1

Not on the ones I've been on, unless you count the useless empty space.

But unlike so many here it doesn't matter to me what boat someone else wants. I just keep wondering why so much effort goes into justifying it to a forum.

If you don't like a topic, the best way to shut it down is to ignore it. If people don't post, it quickly falls off the list recently updated threads.

The OP asked a question. There has been a lot of discussion. Some of it is the same old rehash but this one has done a pretty good job going into the complex issue of how to compare the size of different hull types.

Obviously, we have a group of people who have put a lot of thought into their ideal cruising boat when someone asks, they are happy to share...if you want to call that justifying well...some people just like talking about boats.

[sailorboy1]

Nice "pot or kettle" post.

I certainly wouldn't call this topic "complex" at all. It is really very simple, get the boat you like.

[Polux]

Originally Posted by valhalla360

...
That was my point. A previous post implied that it was rough waves that flip cats yet I've heard of none.
Polux: But I agree that a cat, size by size is harder to capsize due to wave action than a mono but more easier to capsize over a strong gust (monos don't capsize with wind alone). Agreed, but as you indicated big waves typically come with big winds.

Yes but the point here is that big breaking waves don't happen without wind, but huge gusts can happen with no significant waves in several situations.

Originally Posted by valhalla360

...
Polux: A well designed monohull can pass with about 27ft, at 30/33ft almost all monos are approved while cats are only approved around 36Ft and the major brands only start to make cruising cats bigger than that and for obvious reasons while major brands of monohulls start their lines at around 30ft. Actually, there aren't many current cruising cats below 36'. I know at least one that met class A (with minor upgrade package that had nothing to do with the basic design) and a few older models (pre class A standards) that do ocean crossings fairly regularly. Care to list some of the sub 36' models you are thinking of? The ones I can think of are generally not marketed in Europe so they don't concern themselves with the European standards.

The reason most cat brands begun at over 36ft is because it is at around that size that is possible to make them with offshore potential. I am talking about modern cats in production not about old hugely heavy cats.
There are plenty of smaller coastal cats, not approved as class A boats. It comes to me as a surprise they only exist in Europe. They are a nice coastal cruising option. Some of my favorites on that size:

The Edel 33

Aventura 33:

And a performance cruiser cat, the Dazcat 995:


All of them Class B boats and unsuitable to be approved as Class A.

Originally Posted by valhalla360

Polux: A 38ft monohull cost about 70% less than a 38ft cat so for the ones that don't have the money for a bigger cat and can have an offshore boat, monohulls are the obvious answer. Classic flaw in this discussion. A 38' mono is typically equivalent to something in the 30-34' cat. Or vice versa, a 38' cat is equivalent to a mono a little shy of 50' in terms of space. As stated several pages back, I think this is one of the big selling problems for Cats. People who decide they want a 38' boat then see that a 38' cat is much more expensive so they decide cats are more expensive and rule them out before accounting for the differences.

A 38ft feet cat is an offshore safe boat but providing it is an heavy condo cat because if we are talking about really performance cats the size of the cat, to have the same seaworthiness will have to increase and it is not by accident that Lagoon starts its series with a 38ft boat, Fountain Pajot with a 40ft but brands of performance cruisers like Outremer starts with a 45ft cat, Catana with a 42, Le Breton with a 45, Atlantic with a 42. I believe the size is more about meeting market demands. Across the board builders of large cruising boats have thinned their small boat models. I'm talking about cat, mono, power sail...there has been a move to ever larger boats.

Here I guess you didn't understood what I mean. I agree that probably a boat like the Aventura 33 has more or less the same interior space as an Oceanis 38 but a 33ft cat is a coastal boat.

If you want an offshore boat with some reserve seaworthiness and stability over the minimum demanded to be a class A boat, the Oceanis 38 is a suitable boat but what corresponds to that seaworthiness, it is not a 33ft cat, that cannot even be approved as a Class A boat, but an Lagoon 380 that costs over 70% more than an Oceanis 38.

That is why I am saying that if you want an offshore boat at a much lower price you have to chose a monohull. That does not apply if you want only to coastal cruise and then a coastal cruiser like the Adventure 33 can be an option, probably with a similar price, or just a bit more.

Originally Posted by valhalla360

Polux: Regarding performance cats they imply a awareness and a care regarding sailing that are dispensable in a performance monohull and even more in an heavier cruising monohull. Ignoring the heavy cruiser tag on for the moment, the idea that you can just ignore awareness with a high performance mono is a recipe for death and destruction. If you have a heavy condomaran and sail conservatively, you will likely meet or beat the heavy cruising mono and it will be almost impossible to flip the condomaran. Keep in mind, if you are talking heavy wave & wind action combined, there is typically time get the sails reefed.
..

That one I don't get it. The reason why cats have, while doing long range cruising, have a similar performance to monohulls is because they have to be sailed more conservatively.

Even if we talk about a performance monohull the risk of a really strong gust in the night is a broach, that has nothing to do with destruction, more of an inconvenience. A cat can be capsized by a really strong gust so at night, or even during the day without a crew at the lines, ready to let go, it has to be sailed in a more conservative way. That is pretty evident.

He have here cat sailors saying that double reef at night, I have a monohull performance cruiser and the only concession I do at night is that if it is too close to the reefing point (more 5K) I will reef, more to not have the trouble of doing that while I am trying to have some short naps (I sail solo at night) than for anything else.

I am not taking any special risk doing that. The boat is easy to reef and will not capsize no matter the gust and at night, except if there are only weak winds, I am always harnessed to the boat.