Plywood power-cat that also sails?

dancrane

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Not sure why I thought of this. Apologies to anyone thinking I was looking at a boat already built.

I'd like a small sailing yacht, but I don't relish the long hauls at displacement-speeds, getting to where the sailing's good.

I'm time-poor, and fairly cash-poor; not so much that I've begun looking at the MacGregor 26, but it's a persuasive concept.

Is there a way to incorporate 25 knot speeds under plenty of outboard power, with reasonable sailing performance?

Or do the requirements for a fast power-cat, preclude use for sailing?

Cat hulls look simple enough to multi-task, so why haven't I seen a motor-sailing catamaran which really motors?
 

prv

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I'd like a small sailing yacht, but I don't relish the long hauls at displacement-speeds, getting to where the sailing's good.

I've had the same thought. To my mind the solution is a trailer and something to tow it. Even with a big outboard and a planing hull, I can't see anything with a mast doing 60mph ;)

Pete
 

atol

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pretty much any cat will work as a power cat,just put bigger motors in it and reinforce structural members to support the added horse power
 

Neeves

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Chamberlin is a respected designer of sailing cats but he had a couple who had a sail cat and wanted to get to the destination a bit faster and designed this:

Foreign Affair departs

I was not so keen on the interior - but that was a personal choice of the owners. I met them when they arrived in Hobart. It was almost 10 years ago now - not sure what has happened since.

Do a search on Chamberlin, Schionning and Grainger - all respected designers of both power and sail catamarans - they may have something that fits your needs. Look also at the Fusion 40, though it might be a bit big and pricey. Its a neat concept. Seawind built a cat that could be dismounted and packed in (I think) 2 x 20' containers. It was moulded in Korea but never really caught on - but there might be one or 2 around (and for sale). Simply contact Seawind direct and ask.

Seawind 950: Some Assembly Required - Practical Sailor

That should fill a few evenings of research :)

Jonathan
 
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Mister E

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The cheapest way I can think of, is an 8 meter Catalac with an outboard motor.
Stick a big outboard on the back but do not put any water in the two rear water tanks.
To reduce Windage you can lower the mast into an A frame at the rear.
 

TernVI

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....

I'd like a small sailing yacht, but I don't relish the long hauls at displacement-speeds, getting to where the sailing's good.

...
If you don't want to sail at displacement speeds you don't actually really want a yacht at all.
You might want to re-think 'where the sailing is good'.
If your concept of 'good sailing' excludes where you're based, don't start from there, base the boat somewhere nicer?

Much of the UK South Coast, there are places where people base boats away from what I'd call good sailing water, but you can't blast out to open water at 25knots, there's a speed limit.
The only place I can think of offhand where I might want to go fast to get from a mooring area to a sailing area is Southampton Water. Which is why anyone with any cash bases their boat on the Hamble, nearer open water, if they want that sort of sailing.
Other people base their boats at the tops of the harbours and don't fret about it taking an hour to or from the open sea. It's not a big deal when you're taking the boat out for a weekend rather than a couple of hours.
 

Boathook

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The cheapest way I can think of, is an 8 meter Catalac with an outboard motor.
Stick a big outboard on the back but do not put any water in the two rear water tanks.
To reduce Windage you can lower the mast into an A frame at the rear.
There is an 8m with twin 40 or 60 hp motors. It motored at around 12 knots. The sterns had been modified to take the extra weight of the larger engines and all the fuel required.
 

Stemar

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The simple solution is to get a boat that ticks the boxes you want, and park it "where the sailing is good".

Covid apart, travel is easy unless you're loaded down with a boat, when the fuel costs of getting any distance at 20kts will break you, and it still takes a long time compared with driving or flying. Plus, weight is the enemy of speed, especially on a cat, so any sort of sailing boat that will motor all day at 20 knots will have similar luggage allowances to Ryanair...
 

langstonelayabout

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When we were owners of a Pegasus 700 we met up with a family who had the same boat as us that trailer sailed theirs from their home. Every year they holidayed on board in a different part of the country and spoke highly of their experience. He did drive a Discovery so towing was no problem.

Based on what I've seen and heard, the MacGregor 26 is the boat for people that don't really appreciate sailing. An old colleague had one for few years but never had the confidence to sail from the Solent to Cherbourg as it never felt 'right' compared with boats that were designed to motor or boats that were designed to be sailed. The MacGregor hull design is a serious compromise between the two and the rig isn't particularly efficient although it can be set up well.
 

Concerto

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If you want to sail fast then get a Dragonfly trimaran. The 800 is for trailing, so could fit the bill but with limited accomodation.
Used Dragonfly for sale (Sailing Boats) | TheYachtMarket

Triassic of this parish has a small trimaran (not a Dragonfly) that he tows to sail all over the UK and Europe. He regularly hits 15 knots under sail. Perhaps he will see this thread and comment.
 

Mister E

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There is an 8m with twin 40 or 60 hp motors. It motored at around 12 knots. The sterns had been modified to take the extra weight of the larger engines and all the fuel required.
I have seen a video of that one. Ours will do about 7 knots with its Honda 15 hp.
 

Laminar Flow

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By the time you've spent all the money, either converting an existing boat, never mind building one, to meet your motoring speed requirements you might just as well just buy a proper one in the first place and still have some cash to spare.

My old neigbour spent 50.000 CDN $ on building a 23' ply sloop. She was lovely, though. Still.
 

dancrane

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Thanks all, for sharing your thoughts. It was only a late-night ponder, but I still find the theory persuasive.

Sail is great if the wind's going roughly your way; but after 40 years' sailing, off and on, I am unconvinced it's worth fighting a wind on the nose. I was thinking that instead of a yacht built primarily to sail (with an auxiliary as an afterthought), how about a full-on fast comfy motorboat with the power to really shift, yet retaining the option to sail when conditions make it effortless?

I've had motor-sailers in mind for decades. It only occurred to me more recently that the best way to get the most from a 'pure' sailing yacht that isn't very thrilling under sail, may be not even to try, but instead to make the most of the motor-aspect, and never raise sail unless it'll be a sleigh-ride downhill with a following wind.

It's not as if keeping one's hardware, sails, spars, reefing and rigging updated to maximise sailing performance, works out cheap beside the motorboater's fuel outlay. Sailing is a terrible price, but paying specifically to sail, commits you to yet more seasons spent dawdling and heeling, rarely getting directly or predictably to wherever you had left home with hopes of visiting.

If you were able to regard powering to your destination as the core pleasure of boatowning (presumably, motoryachtsmen do) then also being free to enjoy those obliging winds that blow from astern and push you a few free miles, would add a very pleasing, unstressed, serendipitous feel to cruising.

I think most boats that are called motor-sailers, spent their design-time making them sail, and came out as dull motorboats. At the same time, lack of refinement of many sailboats' auxiliaries encourages hitting the 'off' button sooner than might be ideal.

I doubt the 75% motor / 25% sailer concept cannot be done for design reasons. It just hasn't been done much, yet. To my mind it certainly needn't be a multihull, I just thought they're easily driven, and as a sailor of old, I prefer efficiency. ;)
 
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Laminar Flow

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Thanks all, for sharing your thoughts. It was only a late-night ponder, but I still find the theory persuasive.

Sail is great if the wind's going roughly your way; but after 40 years' sailing, off and on, I am unconvinced it's worth fighting a wind on the nose. I was thinking that instead of a yacht built primarily to sail (with an auxiliary as an afterthought), how about a full-on fast comfy motorboat with the power to really shift, yet retaining the option to sail when conditions make it effortless?

I've had motor-sailers in mind for decades. It only occurred to me more recently that the best way to get the most from a 'pure' sailing yacht that isn't very thrilling under sail, may be not even to try, but instead to make the most of the motor-aspect, and never raise sail unless it'll be a sleigh-ride downhill with a following wind.

It's not as if keeping one's hardware, sails, spars, reefing and rigging updated to maximise sailing performance, works out cheap beside the motorboater's fuel outlay. Sailing is a terrible price, but paying specifically to sail, commits you to yet more seasons spent dawdling and heeling, rarely getting directly or predictably to wherever you had left home with hopes of visiting.

If you were able to regard powering to your destination as the core pleasure of boatowning (presumably, motoryachtsmen do) then also being free to enjoy those obliging winds that blow from astern and push you a few free miles, would add a very pleasing, unstressed, serendipitous feel to cruising.

I think most boats that are called motor-sailers, spent their design-time making them sail, and came out as dull motorboats. At the same time, lack of refinement of many sailboats' auxiliaries encourages hitting the 'off' button sooner than might be ideal.

I doubt the 75% motor / 25% sailer concept cannot be done for design reasons. It just hasn't been done much, yet. To my mind it certainly needn't be a multihull, I just thought they're easily driven, and as a sailor of old, I prefer efficiency. ;)


I think the main decision is whether you want to cruise or not. This, in my opinion, determines the choice between displacement or planing craft. Catamarans may be regarded as a special case, but they are very load sensitive, none the less. In my experience all cruising boats with a minimum of autonomy and creature comforts are really displacement craft, unless of course they are proportionately quite large. A displacement craft has obvious boundaries as to it's performance.

The minimum SA/Displ ratio for a boat to be considered a sailing boat (i.e. sail to be considered a main means of propulsion) is 13.
A ratio of 8 or below is at best a MoBo with steadying sail.

In this sense, most traditional motorsailers are not sailing boats. That includes all of the Colvic Watsons and all of the Fishers. They are at best 70/30s. Fisher 34 is 11.64, Fisher 37 is 12.73, Watson 32 is 9.4, watson 35 is 8.6,( all calculations with 150% genoa). The Nauticat 331 with the fin keel comes in at 13.93 and a nasty price tag.

However, all of them will motor you to your destination at displacement speeds and against wind and tide, though going faster than a relative speed of 1 will not be economical.

To plane a boat has to have a very low Length/Displacement ratio, under 100, preferably less. The lines required for planing are entirely different than those useful in displacement craft. The McGreggor achieves this by using water ballast and rather light scantlings. I have seen similar concepts, larger, much more expensive and custom. No matter, at the end there seems to be something not quite right about the concept: You race at 20 kts to your preferred cruising ground and then putter about at 5-6kts (at best) - really?

I have some experience with motorsailers; I have owned two so far. On our current, a Watson 32, I have spent considerable effort (mostly intellectual and just a bit of cash) improving it's sailing ability. We now motor 75% less of the time while cruising. This involved increasing our SA by 100% and cleaning up the hydrodynamics around her rudder. It does not make her a racer, of course, but we have averaged 6kts under sail over 210 miles and 6.8kts over 70 miles. She does go to weather, but she will never be an ace at it, ketch rig and all. For that we have a large engine, like most cruising auxiliaries today and all this at displacement speeds, of course.
 

Neeves

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Your idea of the catamaran is slightly flawed - cats are not really very fast down wind. They are fast off the wind - or reaching. We would not choose to sail to windward, not because cats cannot sail to windward but commonly sailing to windward means sailing into seas (that develop from the headwind) and this is not particularly comfortable - when waiting a day later means the conditions are better. If you sail in a responsive monohull you can steer to miss the breaking waves - much more difficult in a cat (as you have 2 hulls and missing a breaking sea with one hull means you might catch it with the other). Sailing downwind in a cat means you sail with the seas but most cats are simply not geared up with big symmetrical spinnakers (and poles). You could option the gear - but you would have an enormous sail, a bit of a handful if there are just 2 of you.

But reaching - absolutely magic! There is something immensely satisfying, under autopilot, sailing flattish, stirring the porridge in the galley averaging 10 knots, peaking 15 knots - in a 38' cat all weighed down with food and kit for 3 months.

The downside, with your equation - we motor sensibly at around 5 - 6 knots, one engine. We can go faster, 2 engines flat out (7.5knots, flat seas, clean hull) - but fuel consumption increases geometrically.

Jonathan
 

penfold

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Not sure why I thought of this. Apologies to anyone thinking I was looking at a boat already built.

I'd like a small sailing yacht, but I don't relish the long hauls at displacement-speeds, getting to where the sailing's good.

I'm time-poor, and fairly cash-poor; not so much that I've begun looking at the MacGregor 26, but it's a persuasive concept.

Is there a way to incorporate 25 knot speeds under plenty of outboard power, with reasonable sailing performance?

Or do the requirements for a fast power-cat, preclude use for sailing?

Cat hulls look simple enough to multi-task, so why haven't I seen a motor-sailing catamaran which really motors?
You want the moon on a stick. There are boats like that but you need either the ability, drive and budget to build DIY or a cheque book that can pay someone to build it for you. To obtain high speeds like that you need either huge amounts of power with attendant fuel consumption, weight etc, or very light displacement; the latter at least has the merit of frugal operating costs although it's fair to say both compromise liveability in terms of accommodation. A very light multihull like those of Kurt Hughes are about the only practical way of doing it.

26tri40.gif
 
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