Catermerans for blue water?

[Talbot]

My catalac goes better to windward than Noah's ark. Just need to use a 'jib' rather than a genoa. I still keep the genoa on board ready to use but just keep to the jib on the furler.

Yse they can - but most are not set up right. My best windward achievement was 11kts through the water with the apparent at 35 degrees. But I had modified the genoa and the sheeting system, and I was pushing her very hard (was fun though). A lot of the poorly set up ones cant even achieve a VMG of 2 kts.

 

[Sybarite]

Mondern cruising cats .....

Sophisticated weather rooting is the only way round it. .

Last edited by jamesjermain; Yesterday at 18:38. Reason: proof reading

Work in progress?

 

[snowleopard]

Last edited by jamesjermain; Yesterday at 18:38. Reason: proof reading

Isn't an ex-journalist allowed a bit of leeway?

 

[Tropic Cat]

I sail at 35deg to the apparent wind with good speed. My boat does not roll when going DDW or at anchor. Not really that much faster than a similar sized mono but a lot more comfortable to spend time on. (the admiral would not consider spending time on a boat which heels)

 

[rustybarge]

This is a very interesting discussion.

I remember reading that a flat bottomed catamarans only lost 1/2 kt of speed on average, compared to the normal round or v shaped hulls. So is the hull shape on a cat non-critical?

I have just ordered a Cheetah 7.6 motor cat, the one without the wheelhouse. The dimensions are 2.4 beam * 6.7 length plus engine pods which are flat bottomed but do have bouyancy in them to carry the weight of the outboards. The hulls are deep v section, with a narrow bridge deck to act as a shock absorber in short chop using the Venturi effect.

Its the white hull I'm ordering, and I will be removing the windscreen completely. The yellow hulls shows the clearance under the wing deck.

Will this hull sail?
What sort of sail plan would you recommend?
Would just choosing a downwind sail plan be the sensible choice?


Thanks for your advise.

 

[tcm]

yeah, a cat as blue water, def NOT if you are considering eventually/initially using it in the UK.

I have priv495 with 11transats and rtw... blue water you tend to find downwind routes (e.g. most transat and rtw...) and you win in lotsa ways IF you live on the thing.

BUT ... if the boat is gonna be a weekend thing mostly (plus a few longer hols) then a mono is more whizzy fun, more sense. It is not often that sailing the cat is "fun" of itself... but...

the sheer speed probably IS the fun, so recently I was out in the carib with big ocean-type parasailor (vented spinnaker) and that most definitely WAS quite fun, even when the a sheet mangled the fwd steelwork, double digit speeds. But rarely fever do you get the "feel" of the boat with manually helming the thing, it's like driving a train, really . If the "helming feel fun" thing is mega important you need a mono.

I am writing this from the caribbean, and no intention of takinging the thing to the UK.

Sailing pointing er well, you COULD go out and work at it, lightly loaded with some wind i can point 45 degrees ish, choose a victim and rip along but meh, that sorta thinking is not blue water - you wait for the wind or you go on downwind routes. They/We all do.

Bluewater is broad/downwind but on average if living on the thing just one day a week is sailing and the rest of the week is at anchor for which i can carry a 12ft dinghy (remember if you house is a boat your dinghy is your car...) and never ever roll about.

Forget the inverted baloney - you ain't gonna turn the thing over, not really - if loads of them di theta there's be lotsa pix. If you over canvas you break the rig. Comparison of my rig with crusier/racer 50ft monos... it's smaller, on purpose. I over canvas loads of times and um, not an issue.

Liveability-wise get galley UP so you are living on one level.

Stability graphs and significantly favouring BIG catamarans which is probably how i can afford to me more lairy with big sails.

 

[jamesjermain]

This is a very interesting discussion.

I remember reading that a flat bottomed catamarans only lost 1/2 kt of speed on average, compared to the normal round or v shaped hulls. So is the hull shape on a cat non-critical?

I have just ordered a Cheetah 7.6 motor cat, the one without the wheelhouse. The dimensions are 2.4 beam * 6.7 length plus engine pods which are flat bottomed but do have bouyancy in them to carry the weight of the outboards. The hulls are deep v section, with a narrow bridge deck to act as a shock absorber in short chop using the Venturi effect.

Its the white hull I'm ordering, and I will be removing the windscreen completely. The yellow hulls shows the clearance under the wing deck.

Will this hull sail?
What sort of sail plan would you recommend?
Would just choosing a downwind sail plan be the sensible choice?


Thanks for your advise.

Motor cats are very different creatures to sailing cats. Lateral stability and lateral resistanceare not issues with the former, nor is load carrying (much). Beam can be reduced, freeboard increased and hulls made flatter and broader. Transoms must be wider and flatter and bows can be designed for wave piercing with less though given to pitch-poling. The boats you show could not carry a rig.

 

[Lakesailor]

Hope 36452 is still around to take note of advice to his 12 year old question!

Well exhumed by the way.

I noticed that this was an old thread. Not to sure why it has been dug up.

I wonder what the Original Poster did over the last 11 years?

They seem to be having fun. Would have been better as a new thread. I notice no-one has acknowledged the Thread-That-Wouldn't-Die status.

 

[rustybarge]

Motor cats are very different creatures to sailing cats. Lateral stability and lateral resistanceare not issues with the former, nor is load carrying (much). Beam can be reduced, freeboard increased and hulls made flatter and broader. Transoms must be wider and flatter and bows can be designed for wave piercing with less though given to pitch-poling. The boats you show could not carry a rig.

Hi James,

Thanks for the advise. I did notice the major differences in the shape of the Cheetah, esp. The small beam in comparison to a sailing cat. The freeboard is actually quite low when the boat is floating as you can see in the photo below. The clearance under the wing deck looks similar to a sail cat.

I think you have identified the problem, it's the small beam, which would make downwind hull dig in because of the deep v section and lack of bouyancy that it provides.

On the basis of 'just downwind', how would a parasail work?

 

[tcm]

jeez that IS an old thread! ... I wondered about the "points better than Noah's Ark" but let tit pass...

 

[rustybarge]

.....but which are older, Catarmarans or monohulls??

 

[sailorman]

Man first used a mono hull.
it was a log & paddle

.....but which are older, Catarmarans or monohulls??

 

[rustybarge]

Man first used a mono hull.
it was a log & paddle

What about those Polynesian outrigger canoes. Are they multihulls, or a monohull with stabilisers? I think it's easier to make a outrigger canoe consisting of full log and a couple of sticks, hollowing out a log for a monohull must take weeks to make.

 

[KellysEye]

The largest number of cats of one make that we saw in the Caribbean were Prouts.

 

[rustybarge]

The largest number of cats of one make that we saw in the Caribbean were Prouts.

Hi Kelly,

The problem I see with prouts is the massive beam, fantastic at anchor......but what marina in Europe will take the prout which is twice the width of a monohull?

I choose a Cheetah cat because it has a beam of only 2.4, and should fit into a standard pontoon mooring.

You may say 7.6 mtr length is too small to live on, but I was looking at the size of wheel houses/ saloons on bigger boats, and most boats including the big cats have only about 18' standing headroom from the windscreen to the transom.......exactly what my Cheetah will have.

What about the cabins? Happy to sleep on camp beds, the one mounted on springy steel legs....seem to Be verly comfortable.

 

[capnsensible]

The largest number of cats of one make that we saw in the Caribbean were Prouts.

Wow, that must have been years ago. Over the last 10 years Ive been visiting there are very large numbers of chater cats everywhere from BVI's to Grenada. All the big players have them, Sunsail, Moorings etc. Lots of the specially made Sunsail ones from South Africa, Lagoons, and many other marqes. Hundreds.

Hardly seen a Prout in all that time, seem kinda old fashioned these days. Sailed a lot on them 20 years ago but dated design now.

 

[geem]

We have recently sold our Prout snowgoose 37 after 11 years and one Atlantic circuit. We had very good sails and a taller than standard rig. We were very weight conscious. The Prouts are built like tanks so are strong but slow down considerably if loaded heavily. We used to average about 7 to 7.5 knots typically on a long passage of 100 miles or so. The best average from Holyhead to Douglas in IOM was 9 knots in f6 with wind just forward of beam and full sail. Our best 24 hr run across the Atlantic, overloaded was 172 miles. We learnt our lesson about weight when we returned from the Caribbean and lighten her by replacing all the plywood bunk tops with foam core. We changed all the doors to foam core too.
We had a single engine and had no trouble manoeuvring in marinas. The driveleg was steerable. Can't imagine the loss in performance with the extra weight of another engine and dragging two props through water!
We crossed from Antigua to Azores with wind on nose whole passage. Bloody miserable bashing to windward for three weeks but found monohulls in Horta had had a similar bad time.
Really enjoyed are time with the cat. One of the few boats you can cross oceans in and dry out on beaches.
Just swapped now for a large monohull that will carry serious provisions, dive gear, ton of water, half ton of fuel. 7 ft draft will take some getting used to.

 

[geem]

Hi Kelly,

The problem I see with prouts is the massive beam, fantastic at anchor......but what marina in Europe will take the prout which is twice the width of a monohull?

I choose a Cheetah cat because it has a beam of only 2.4, and should fit into a standard pontoon mooring.

You may say 7.6 mtr length is too small to live on, but I was looking at the size of wheel houses/ saloons on bigger boats, and most boats including the big cats have only about 18' standing headroom from the windscreen to the transom.......exactly what my Cheetah will have.

What about the cabins? Happy to sleep on camp beds, the one mounted on springy steel legs....seem to Be verly comfortable.

Prouts don't have massive beam. A 37 ft Prout has a beam of 15 ft 3 inch. Not dissimilar proportions to a motorboat. This is a typical length/beam ratio for all Prouts.
Every anchorage we seemed to go in in the Caribbean had an old Prout anchored in some corner.

 

[rustybarge]

Prouts don't have massive beam. A 37 ft Prout has a beam of 15 ft 3 inch. Not dissimilar proportions to a motorboat. This is a typical length/beam ratio for all Prouts.
Every anchorage we seemed to go in in the Caribbean had an old Prout anchored in some corner.

Hi geem,

That's very interesting info. About useful loads on cats and how it affects performance.
When I was ordering my cat the designer kept asking me how much gear I was going to bring, whether I was going to use a canopy, and how much fuel I planned to carry.......Now I know why!!

The guide payload was a max of 500 kg inc. pob. The cat was designed to take twin 40-60. Hp outboards, so taking your advise I'm definatly going to go for a single outboard, The Suzuki 90 ho looks good at 155 kg.......saving 85 kg.over the twin setup.

I've ordered the open version saving about 200 kg weight of the wheelhouse, I think I'll settle for a canopy instead saving more weight.

Thanks again for that info.......so it's going to be an obsession with weight, weight, weight with cats!(must start that diet)

 

[snowleopard]

Prouts don't have massive beam. A 37 ft Prout has a beam of 15 ft 3 inch.

My cat is 2 ft longer and 8 ft wider! No, Prouts are very narrow. In many places they are narrow enough to fit in a standard boat hoist and there are monos not much longer with the same beam. Makes it even more galling in places they charge 50 or 100% extra to tie alongside.

The Island Packet 37 is only 2' narrower!