Monohull or Multihull Sailboat?

[Brent Swain]

North coast logs and driftwood doesn't get along to well with flimsey multihulls. That and moorage difficulties is why you don't see many up here.
Brent


quote=delmarrey]G'day Glen,
From what I understand you boys downunder are putting out a good portion of the multihulls these days. And some fine work too from what I've seen. I've been keeping my eye on the F-41's for a couple of years now. The big Island my be on my shopping cart some day soon. S. Afracia seems to be doing a fair share as well.
Up here in the Pacific NW it's a rare occasion to see a Cat. Some Tri's are around but just the small ones mostly.

fair winds................Del[/quote]

[Brent Swain]

In New Zealand a lot of offshore multihull sailors are dissappointed with multihulls. They are only fast for local sailing where they can be kept light. For long distance cruising where you have tr to carry supplies( unless you want to have to buy them where they are extremely expensive and always be on the verge of running out) and gear they are anything but light or fast. Their daily milages are no better than monohulls and you have more hulls to maintain.
Brent

[beau]

Can someone explain to me WHY multihulls are so slow when loaded down.
Is it just the increased wetter surface (which doesn't make sense) or is it the increased wave making resistance?

beau

[cat man do]

Originally Posted by Louis Riel

In New Zealand a lot of offshore multihull sailors are dissappointed with multihulls. They are only fast for local sailing where they can be kept light. For long distance cruising where you have tr to carry supplies( unless you want to have to buy them where they are extremely expensive and always be on the verge of running out) and gear they are anything but light or fast. Their daily milages are no better than monohulls and you have more hulls to maintain.
Brent

From My observations in New Cal, and reading Multhull world, it seems that there is a lot of large cat's are beimg launched for cruising.

In New Cal, it seemed it was mainly multi's clearing in through custom's

Carrying supplies is not much of a problem as you are only a week from the shop's in a cat due to the speed. carrying a month's worth of food is more an issue of space and refridgeration and keeping fresh food edible, not load carrying ability.

The modern style of performance cat's built in Oz and NZ, while not having a huge payload still carry enough for most while retaining a lively sailing characteristic, faster than nearly any Mono.

These are usually not factory /production build's

If overloaded or of heavy build/ displacement to waterline length, they will perform more like a monohull speed wise to widward, but will usually still flog them of the breeze, without heel, or broaching problem's.

Beau, it is purely a power to weight equation like a car.

Big HP/Big sail VS light weight/long waterline = fast

Low HP/ Small sail VS heavy/ shorter waterline = not as fast.

Probably not the best example but my last cat ,30 ft, cruiser /racer would still win fun races carrying dive gear, 8 ft dinghy, big box of book's, 3 week's worth of food and and piss for Africa, yet still sail at 6 knot's in 7kn, and off the breeze we had cracked 19kn on ocassion comfortably.

Put 2 extra bodies on board and she felt slow, more a feel than anything else, would sail at around 4 kn in 7, in 15 kn of breze sailed well, but threw a bit more water around, and still did fairly numbers in heavy air.

She just felt heavy and a bit sluggish and unhappy, not like a big dinghy.

Dave

[44'cruisingcat]

When you say so SLOW, they are usually still faster than an equivalent length mono. Just not by as much as they should be. Most multi's have relatively long slender hulls which arent as bouyant as much fatter monohulls, so their immersion rates are faster per kilo of load.

The main point is to use a multi for its intended function - a race boat will be affected much more than a cruising design, and some cats can carry very large loads - they are designed to. Their is a Roger Hill designed Tasman C35, a 35 foot cat that is in survey to carry somewhere around 35 passengers.

[cat man do]

Originally Posted by 44'cruisingcat

When you say so SLOW, they are usually still faster than an equivalent length mono. Just not by as much as they should be. Most multi's have relatively long slender hulls which arent as bouyant as much fatter monohulls, so their immersion rates are faster per kilo of load.

The main point is to use a multi for its intended function - a race boat will be affected much more than a cruising design, and some cats can carry very large loads - they are designed to. Their is a Roger Hill designed Tasman C35, a 35 foot cat that is in survey to carry somewhere around 35 passengers.

But this is proof that some of the rules are made by idiot's.

35 people standing up maybe, they dont have that much deck space for sitting lounging room , and she would be well down on her lines.

In the creek at 1770 about 10 years ago, there was a Seawind 24 for sale in survey for 14 + 2, could you imagine 16 people on one of these?

I freaked out taking out 6 people for a pleasure sail for the day on mine.

Dave

[44'cruisingcat]

The hulls are actually designed to carry that kind of weight. There is one used in Hervey Bay for whale watching, although I doubt they would ever take 35 passengers out, but she manages 20 odd fine. But remember the C35 is not a performance cat by any means.

[cat man do]

Is that the one from Kingfisher Bay?

It is minus a cabin if I remember correctly, so that would give her more room and save a few hundred kg as well.

You are right about not performance, more like a modern Inspiration 10.

Nice and comfy.

Dave

[southernman]

hey you aussies what do you think of the schionning designs cats?

[schoonerdog]

Beau,

The following link is from African cats, which makes a very high performance cruising catamaran. It explains how catamaran speed is affected by weight.
African Cats: comfortable lightweight performance leisure catamarans

[44'cruisingcat]

Originally Posted by southernman

hey you aussies what do you think of the schionning designs cats?

I like them. Good looking, fast boats. I don't think I would build one, but if I could afford to I would buy one.

[Sailormann]

I guess I am a bit of a luddite, but I remember reading about multihulls breaking up in heavy seas - the crossbeams that held them together came loose or cracked or something so there were two unstable hulls and no rig, and then there was one that turned turtle... I think that they are ideal for coastal cruising/island hopping. No disputing the fact that there is lots of room, but for serious offshore work in heavy weather I think the monohull is the better bet...

[beau]

yes, and mono,s lose there keel and sink to the bottom

[Sailormann]

I guess we need to decide which particular death we find least offensive

[44'cruisingcat]

Originally Posted by Sailormann

I guess I am a bit of a luddite, but I remember reading about multihulls breaking up in heavy seas - the crossbeams that held them together came loose or cracked or something so there were two unstable hulls and no rig, and then there was one that turned turtle... I think that they are ideal for coastal cruising/island hopping. No disputing the fact that there is lots of room, but for serious offshore work in heavy weather I think the monohull is the better bet...

That's a bit like saying "them new fangled automobiles aint as reliable as my old horse and buggy"
You are talking about multihulls from quite a long time ago. Modern ones don't break. The designs and material have improved out of sight.
Many multi's have circumnavigated now, in all kinds of weather.
The seaworthiness argument really doesn't hold water any more.
Your'e entitled to your own preference, but seaworthiness just isn't any more of an issue with multihulls as it is with mono's.