Multihull Size in a Mono Hull Package

[Dockhead]

Originally Posted by StuM

I'm with Sand Crab. 30-50% longer is a fairly good figure with faster cats more around the 30% end and condominiums towards the 50% end.

You can do the math simply with the beams. But certainly not 50%. My 54 foot mono, sleeping 7, has more hull volume than a 45 foot cat.

[Steadman Uhlich]

Originally Posted by Dockhead

You can do the math simply with the beams. But certainly not 50%. My 54 foot mono, sleeping 7, has more hull volume than a 45 foot cat.

But does it have four heads??

And a 45 foot cat probably sleeps 10 with four double bunks in four staterooms (each with a private head) and two on a saloon settee.

[Polux]

Originally Posted by Steady Hand

Consider a Catamaran that is 44 feet may commonly have FOUR double staterooms with FOUR heads.

To find that on a monohull, I think you would have to go to a 70+ foot mono.

I would prefer to handle and replace ($$) the sails (and other gear) on a 44 foot cat, rather than a 70+ foot mono.

I don't understand where you got those notions. In fact you can have 4 cabins on a monohull since 46ft. I will show you: The Bavaria 46, the Oceanis 48 and the Hanse 455.



To be honest you find 4 cabins of about the same total area on a 42ft cat, if it is a fat (slow) one like the Lagoon:

[markpierce]

Four bedrooms? Who can stand living with eight people on a small boat! Maybe you can, but I can't. It has always bugged me how boat designers try to cram so many berths on a boat.

[Polux]

Originally Posted by Sand crab

.. Sails on a mono would be bigger (although many older designs are ketch rigged) and draft too. Deep draft is good for a mono in the open ocean.

If we compare the sail area of the Lagoon 421 (102.3m2) with the one of the Bavaria 46 (108m2), the Oceanis 48 (112m2) and the Hanse 455 (103m2) we can see that there is no significant difference at least one that has influence in what regards dificulty in sail handling.

Originally Posted by Sand crab

Even on larger cats the sail handling is much easier because of that lack of heeling and wide flat decks. Most cat sailors don't generally wear safety gear except sometimes at night or rough weather while on a mono it's just about standard if going forward.

We are not talking about larger cats, we are talking about a smaller cat versus bigger monohulls that will have a softer less jerkier motion in waves. Really, it is about standard on a 45ft monohull to wear safety gear to go forward without rough sea? I wonder where you got that notion but I can assure that out of rough weather on a 45/50ft monohull nobody wears safety gear to go forward and the sail handling on modern boats is quite easy:they heel just about 15/17º

I just hate this kind of senseless arguments. If someone prefers condo cats over monohulls, what is the problem? Not calling condo cats as in an offensive way, just to separate them from performance cats because on one of those you will not put 4 cabins on a 42ft boat, you will need at least a 45ft cat to do that.

Condo cats go well downwind but are a pain in the ass upwind. If we compare the performance of one (42ft) with the one of one of those 45/50ft, the downwind performance would be close but upwind the monos will sail way better. It is all a question of personal taste and what one looks in what regards sailing and living space.

The advantage of condo cats goes all to a saloon with better all around views and most of all a better cockpit area. Regarding the views and the saloon it is a mixed blessing: I would not want a monohull with a deck saloon for the Med or Caribbean. Yes the view is nice at night but during the day is just too hot and those "glass" panels have to be covered and then no view anymore, not to mention the hassle. Of course you can have AC and a generator but that does not make my style, even if it can make the style of many.

[Polux]

Originally Posted by markpierce

Four bedrooms? Who can stand living with eight people on a small boat! Maybe you can, but I can't. It has always bugged me how boat designers try to cram so many berths on a boat.

I agree with that. Cats and monos of this size and so many cabins are for charter work. They have other versions with less cabins, what they call an owner version.

[Steadman Uhlich]

Howdy Polux.

I appreciate you posted those photos (plans) of the other boats, as seeing something like that is always helpful.

But, in looking at some of those monohulls that have 4 cabins in 40 feet, I see those cabins but to me they don't look that inviting as the forward staterooms split the "V" bow shape into two very narrow "doubles."

I suppose I have been looking at too many 40+ft mono yachts that have nice aft stateroom (owners) and generally one more forward with a double. On larger mono yachts than that (44, 50, 63 ,70, etc) I enjoy seeing even larger spaces and very nice owners aft staterooms.

So, I stand corrected (by your illustrations): One CAN buy a 40 foot mono with FOUR "double" (if small and likely cramped) staterooms (and 2-3 heads).

That said, I don't think I would want to be shoehorned into such small cabins if I were buying my dream boat and I was the owner planing on living aboard for a long time or cruising for years.

My choice would be for a 40-45 foot mono with just two staterooms max with one being a nice spacious owner's stateroom with a double, two heads, or a 40 foot cat with an owners version (owner gets one hull).

Anyway, it is good to see there are many choices.

[Polux]

Originally Posted by Steady Hand

Howdy Polux.

I appreciate you posted those photos (plans) of the other boats, as seeing something like that is always helpful.

But, in looking at some of those monohulls that have 4 cabins in 40 feet, I see those cabins but to me they don't look that inviting as the forward staterooms split the "V" bow shape into two very narrow "doubles."

...

Anyway, it is good to see there are many choices.

Hi there!

Look again at the post. The monohulls are a 45, a 46 and a 48ft. No way of putting 4 cabins in a 40ft mono and hardly on a 40ft cat.

Yes I agree with you. It is nice such a big choice that allows us to find on the market what you want even if in what regards that the Europeans are much luckier since the choice is considerably bigger.

[barnakiel]

There are also some cat like monos. I remember something called (Dufour?) Atoll that was a charter marvel some time back in French West Indies. I have also seen an Eliot design that offered space easily comparable to a cat.

All other tings equal, I would always prefer a design like Ourson Rapide over a cat BUT there is only one Ourson Rapide built as far as I know.

So it is a multi that is the future. At least for now. And I am just waiting for a day when Lotto numbers will be some easy combination. I will keep our mono then and buy either a Breton or an Outer/Catana sort of toy as a daysailer.

PS I think many 40' cats are about the volume, space and comfort of an average 70'er.

b.

[JPA Cate]

Originally Posted by Tscott8201

So everyone knows that cats have more square footage per linear foot than mono hull boats due to the wider beam. Also, in general the cost of a mono is considerably less than a cat for similar lengths. But that equality doesn't help much since the square footage on board is so drastically different. So when comparing monos to multis, what lengths of each design are similar in square footage (i.e. if one were to look at the room on a 40' cat, what length would a mono need to be to give the same space?).

Also, what other factors creep into the picture as the size of a mono increases that would affect maintenance costs and sailing ability as it pertains to a small family. For example, I assume the sail plan on a larger mono would become substantially larger and therefore harder to handle as compared to a cat of similar square footage. Draft would also seem to become a factor as the drafts on a mono become much greater as they grow in size.

Any information that would make comparing apples to oranges a little easier.

Tom

Hi, Tom, Great avatar photo!

I think you left out the fun to sail part, but nevertheless, if it is a small family, then perhaps a 3 cabin Adams Naut 40 might work for you.

Our Sayer 46 one off has 3 cabins as well, and, even overladen in cruising trim can be fun to sail. However, she draws 7'2" (2.2 m.), so that might be a problem for you--and this boat isn't for sale at the present time.

So what you probably will benefit from is going to look at a whole bunch of boats, monos and multis, and then, suddenly, when your hear beat increases and the corners of your mouth turn up, you shall have found her.

A forum is possibly not the best place for this discussion because the enthusiasts are not perhaps realistic in what they write, but after you firm up your ideas about how much room you'll need (and how many heads you want to maintain), and including what kinds of boats you and your good lady like to sail, then you'll be in a position to know.

Another factor is where does your sailing experience lie? Because if you've 20 or more years in one, then you toss that out when you shift, and may have to live with never becoming a great sailor of the new type.

For ourselves, we were very close to buying a Catana 44 that had been stretched to 47 for additional flotation, and Jim's heart went pitty-pat: it had been recently (some months) re-fit in NZ. Then our present boat became available, and we snatched it up, thus maintaining our mono skills.
Although the Catana was a nice boat, and would have seen us pretty well I think, we've no regrets.

FWIW, I'd be reluctant to undertake a circumnavigation in most cats I've seen.

Ann

[barnakiel]

Then again, one thinks of the space vs. the utility.

In multis, some of the space is in the hulls, and I know people who do not like living (sleeping first of all) in coffins.

So, it takes a huge cat to get to the cabin spaciousness and height of a much smaller mono.

Another grumbling is the bridgedeck area - not everybody likes living in a glasshouse, especially in the tropics. True, the amount of light is great unfortunately on too many boats it gets way to hot in there. New boats with vertical windows are much better in this respect.

Off course, as time progresses, older shortcomings are addressed and we see better and better interiors. New (production cats) look like bricks, but inside they are way above and beyond the older batch.

b.

[Rohan]

Originally Posted by Steady Hand

But does it have four heads??

And a 45 foot cat probably sleeps 10 with four double bunks in four staterooms (each with a private head) and two on a saloon settee.

But how comfortably? The charter version of the Leopard 44, for example, has four regular cabins and four heads but the heads are pretty much the bare minimum in size to be usable:



A 44' cat with double the beam of a 44' monohull doesn't have double the interior volume. This is because the cat has a huge empty space in-between, usually filled by the large trampoline (cats like the Geminis are an exception). The trampoline is a great lounging area, but I still wouldn't consider it a "living space" although some might disagree.

About 1/3 extra usable living space of a catamaran vs. a monohull of same length seems to be about right. Trimarans would be computed differently depending on how they are set up.

[thinwater]

Originally Posted by markpierce

Four bedrooms? Who can stand living with eight people on a small boat! Maybe you can, but I can't. It has always bugged me how boat designers try to cram so many berths on a boat.

Perhaps this correlates to why I have only one child.

[valhalla360]

Originally Posted by Polux

I just hate this kind of senseless arguments. If someone prefers condo cats over monohulls, what is the problem? Not calling condo cats as in an offensive way, just to separate them from performance cats because on one of those you will not put 4 cabins on a 42ft boat, you will need at least a 45ft cat to do that.

Condo cats go well downwind but are a pain in the ass upwind. If we compare the performance of one (42ft) with the one of one of those 45/50ft, the downwind performance would be close but upwind the monos will sail way better. It is all a question of personal taste and what one looks in what regards sailing and living space.

The advantage of condo cats goes all to a saloon with better all around views and most of all a better cockpit area. Regarding the views and the saloon it is a mixed blessing: I would not want a monohull with a deck saloon for the Med or Caribbean. Yes the view is nice at night but during the day is just too hot and those "glass" panels have to be covered and then no view anymore, not to mention the hassle. Of course you can have AC and a generator but that does not make my style, even if it can make the style of many.

Since most cruisers spend better than 90% of thier time at anchor or in a slip, the living space is critical as long as it's sea worthy and has reasonable performance and most codo-marans will beat the typical cruisng mono.

If performance is your critical feature, how long of a mono do you need to run with the gunboats and similar performance cruising cats? Assuming a 15kt criteria for a 50' gunboat, hull speed formula suggests something on the order of 120-140' mono.

[Polux]

Originally Posted by valhalla360

Since most cruisers spend better than 90% of thier time at anchor or in a slip, the living space is critical as long as it's sea worthy and has reasonable performance and most codo-marans will beat the typical cruisng mono.

Yes, that's why they are called condo cats. They are unbeatable at that, I mean offering space while at anchor or at a marina or port. But there are a lot more that pass their time at the marina or port than at anchor (all year long) and there the space remains but the price will go up 50%, 60% or more regarding a monohull with the same size. Even a bigger monohull will pay less, not to mention there are places where the cats are simply not welcomed due to lack of available space.

Originally Posted by valhalla360

If performance is your critical feature, how long of a mono do you need to run with the gunboats and similar performance cruising cats? Assuming a 15kt criteria for a 50' gunboat, hull speed formula suggests something on the order of 120-140' mono.

Most cruisers cannot afford a Gunboat and regarding performance cats they don't offer the same kind of accommodations and space as condo cats, at least in what regards affordable sizes. Also while a performance 30ft can be already an offshore boat, a cat needs to be substantially bigger to offer the same degree of seaworthiness, specially if it is a light performance cat.

In the end it is all a question of money and personal preference even in what regards sailing.