Which one out of these small multi-hull designs will be the best for my needs?

Greetings and good day,

This is my first post here. I have been browsing the forum for a while, collecting pearls of wisdom and experience.
A little bit about myself: I have been sailing in childhood for many years. However, I have far less experience
in boat design and multihull than many gents here. For a long time, I wanted to build a sailing boat for me and my family.
Life is short, live your dreams; The more time passes - the more you realize the truth in these words.

I chose a Catamaran sailboat due to safety, comfort and speed.

Design parameters - a vessel that is fun to sail and race during weekends, and is also able to
take a small family for a few weeks per year cruise in the Mediterranean, during the summer season.

Desired features:
1. A fully enclosed center-cockpit helm, with all lines led to the cockpit for safe operation.
2. Fast.
3. Easy to build and maintain.

At the beginning I was looking at Dix Catamarans, in particular Dix 430, which is a very nice design in my opinion
(except the small outside hangout space, which can be fixed). However, the build time of the radius chine construction
is about 8000-10,000hrs, with a projected cost of over 300K USD. We are not rich, just ordinary folks - so I looked
at smaller and more affordable 26ft-33ft multihulls that can be built at home in 1000-2000hrs.

The three designs I liked the most after a long search, that can be customized to our needs, are:

1. Eagle 24
This is a real "gem" by Richard Woods, with an empty weight of 650kg and displacement of 1250kg this is seaworthy
small "big" design that punches far above its size. The easiest and cheapest to build on this list, with an estimated 350hrs-500hrs
build time. It should be fast for its size too. The first one built was stretched to 8m. With the designer's permission/guidance,
it can be customized into a nice hard-top center-cockpit cruiser for a small family who are ready to give up some comfort,
in exchange for adventures in a very easy to-live-with cost-effective package.

Pros:
1. Cheapest and easiest to build and maintain.
2. Easy to handle, and also to live with long term.
3. Can stay more in Marinas during cruising, due to smaller size/costs.
4. The only boat on this list that can traverse the French canals.
5. Fun to sail during weekends.

Cons:
1. Lightest and shortest on the list - In inclement weather or during longer legs it would be felt. Not a design fault, just mere size limits.
2. Smallest payload capacity on the list.
3. Smallest room and space.

Eagle 24 photos:





2. DUO 1000
I like Bernd Kohler's designs and philosophy. His designs are down to earth and oriented towards real sailors, not the charter crowd.
The DUO 1000 catamaran is an open deck 10m design that is positioned right in the middle between the KD860 and KD122
(I ignore other duos here in the context of this comparison). It is larger than KD860 at 10m/33ft, but cheaper and simpler to build than
bigger designs like KD122, at about 2000hrs build time. It is the biggest vessel with the longest waterline on this list, and surprisingly large for its weight.
It carries the highest payload of 1600kg on this list, at a total displacement of 3200kg. I have exchanged a few emails with Bernd,
and he drew a sketch of a modified center cockpit bridge deck version which would be easy to build and fits the bill.
From all 3 designs, this is the one I think would feel safest during weather conditions, and would also be the most comfortable overall.
I read some remarks of Richard Woods, where he says that 30ft is about the smallest cat he would take on a blue water cruise,
and I feel that this one is just about the right size for our needs.

From all three designs, I am most leaning towards this one, mainly due to size.

Pros:
1. Longest waterline for its weight, with the biggest payload capacity on the list.
2. More comfortable both at sea and at anchor.
3. Probably the fastest due to its size.

Cons:
1. 2-3 times more expensive, and takes twice longer to build than a customized Eagle.
2. Highest upkeep and Marina costs.

Duo 1000 photos:




3. Siren 8.4
Wow, what a beauty. Looking at it, it is difficult not to fall in love with this design - If I had to choose
solely by heart, this would be my boat of choice. Those fine curved lines and gently flared hulls
remind me of Shuttlleworth and Schionning designs, it combines modern performance with a touch
of an old school.

The first thing you realize looking at the material list is - that this boat is built like a tank.
Very strong and safe, with huge accommodation-to-length ratio due to a modern flared hull shape.
This boat would surely be appreciated by a real seaman in every marina around the world.
The price for the plans is very fair too. The weight is 2000kg at 28ft length, and while shorter than
DUO 1000, it takes the same amount of epoxy (250kg), and equal or slightly larger amount of plywood
to build, using the plywood-epoxy method. Due to this fact, and due to hull shape that involves more work,
I assume the build time will not be much shorter than the DUO 1000.
My estimate is 1500hrs-2000hrs to build. But boy! That would make a one beautiful boat.

Pros:
1. This thing is a beauty! This is not just a boat, but an exhibition of art.
2. Solidly built, modern and spacious hull shape.

Cons:
1. Smaller than DUO 1000, while being close in weight and costing same or more. Less deck space.
2. Personal assumption - that it might be the slowest boat on this list?
3. Flared hulls - are they more sensitive to weight overloading and high seas?

Siren 8.4 photos:


In conclusion:

I tend in the direction of DUO 1000, from all the three designs.
However, there are people with far more experience and knowledge than me in this forum, and
I would be happy to hear your thoughts, ideas and suggestions regarding my choice.

Any input would be welcome.

Best regards,
Eli.

 

The time commitment to build these is immense. A time budget is vital to success. Factors to consider…

On site of builder?
Outside or in?
Full time or part time?

Onsite means you can go glue something up after the workday.

Outside means you spend many hours covering work.

Part time means working half the Saturdays a year or 26•8 = 208

 

I was thinking about building myself in a rented shed, working 20 hrs per week, and more during the holidays.
That makes the time budget about 1000 hours per year. So if a design demands 2000hrs to complete, I estimate
it can be accomplished within 2 years, maybe sooner if hiring assistants for large tasks like sanding and wetting out fiberglass.

 

The Eagle 24 catamaran by Richard Woods seems like a great affordable option for weekend sailing and short cruises. At only 24ft, it punches above its weight with a displacement of 1250kg. The simple construction should make for an easy 350-500 hour build. While small, it can potentially be customized with the designer's guidance into a nice little hard-top center-cockpit cruiser. The biggest trade-off is reduced payload and interior space compared to larger cats.

 

The Duo looks like it would lend itself well to a large hard bimini covering the deck area between the hulls with the boom up high, and a more central helm position compared to the others. You could then make a shower curtain type soft enclosure that could enclose the deck area to protect you from weather that could be rolled up when not needed.

Take a look at the IC36’s enclosure for some inspiration. It has sort of a “convertible” deck.

I like the idea of a nice flat deck that becomes a shaded outdoor lounge area. You’re probably gonna want some solar. Mounting it atop a bimini makes a lot more sense than trying to mount it to hull surfaces.

 

The Eagle is all you need, build that and go sailing. The displacement is just the weight at the designed waterline, it's OK to carry more. It's more a matter of performance than safety.

The Duo1000 and Siren are 2.5 and 3 times the weight of eagle, and probably 2.5 and 3 times the work/cost. It probably also means you are 2.5 to 3x more likely to not finish the boat. Even eagle is a big project. The advertised build time is just the boat ready to paint. But then there is so much more work. The old joke is that when the hull is done and fitted and you are ready to do the rig you are 1/2 way done!

The siren looks good, just a lot more work than the eagle. All those hull panels need to be cut with a jig saw and scarfed then taped, that's a lot of extra work.

The Duo 1000 has some poor design choices in my opinion. The decks are sloped fore and aft, which is a safety hazard. The reverse bow will kick up a lot of spray and serves no purpose. The experimental main sail may have issues and may be difficult to trim properly. I would stay away.

 

To those who took their time reply in this thread so far,
Thank you. You input is greatly appreciated.

Regards.
Eli.

 

My comment on the displacement of the Eagle are based on comments made by the designer elsewhere. Essentially it's expected that people will overload their boats so the structure is designed with this in mind. But the added weight will of course reduce performance, and the hull is optimized at the designed displacement.

As for the Duo, imagine asking your kids to stand on the bow with a line while docking. It's not a good setup. The curve might reduce windage a bit from the front, but it increases windage from the side. I think the traditional profile of siren and eagle are much more functional, and there's a good reason most boats look like that.

 

Hi WB,
In regards of my previous post - I feel it is polite to thank people who take their time to answer a question.

I have bought the study plans for the DUO1000 and Siren 8.4 - the Eagle 24's study plans are free on the website. Courtesy of Mr. Woods.
I am searching for a building place these days - and the decision which boat to build will determine quite a lot:
Beginning with the shed/yard location - the bigger yards are more far away from my home, while hulls and deck of a smaller boat
like the Eagle can be built at the neighbor's yard. Bigger boat will also need different supplies, different financial plan etc.
So basically, the choice what to build is kind of a "bottleneck" right now.... and these few replies with different points which
I did not think about, mean quite a lot.

The cost difference between the three designs is considerable.
But I think the fun factor is the same regardless of size, only with less material stuff being carried along.

About the DUO 1000, the remarks are correct - In the updated design the bows are now straight, and the rig can be conventional.
Regarding the sloped hulls, it would have to be addressed - while functional for interior space, they are less safe outside.
I have already been thinking about necessary design modifications.

Regards,
Eli.

 

In general I would say it's a bad idea to modify designs and better to find something that works for you as is. I think this the number one conclusion that you might arrive at with more experience.

It's also good to build nearby, you'll get a lot more done. A lot of times you will have to do a bit of epoxying, and then wait, so it helps to be able to pop over to the boat for short periods. I know a guy who bought a partially built catamaran 1.5 hours from his house and tried to finish it - that boat ended up in the dump.

I have reservations about Kohler, but OldMulti feels he is competent and I would say his opinion should carry much more weight than mine.

I would personally rather build a Woods design since I feel his credentials and breadth of experience are stronger, and as an engineer his designs make more sense to me. This is just my opinion, take it with a grain of salt. Woods is also very focused on racing and optimizing performance based on racing experience, although some say that focus results in designs that are too spartan - especially with interior accomodations. To be fair, you will find one member of this forum who was the first to build a recent Woods design and had legitimate problems with it.

 

If you're considering a 10m and 8.4m boat, the equivalent Woods design would be the 8.5m Gypsy.
It can be built in 3 sections (hulls + cuddy/bridgedeck) and final assembled at the launch site.
It is a simple design, for economy and quick build. Easier, cheaper, and quicker than the Duo or Siren.
Very well proven, with ocean passages including Panama-Tahiti.
Separate private accom spaces, full headroom, very safe deck layout, good performance.

The first one built in Australia is a regular visitor in my area. I went on board when she first arrived about 25 years ago. Very clever design, amazingly spacious for a small boat that sails really well. Now on her third owners, still cruising the East Coast.

 

Gypsy 1.8T , 2.4T
Eagle 24650kgs, 1250kgs
Eagle 24 cuddy !!! Sailing Catamarans - Eagle 24 open deck easy build roomy cruiser http://sailingcatamarans.com/index.php/designs-2/2-catamarans-under-25ft/455-eagle-24
"take a small family for a few"

Siren 8.4 1650kg + ?????

DUO 1000
Weight empty 1600 kg
Weight max. 3150 kg

Gypsy at 10%= 30' 1,9kg 3.1T beds for 2+3 liters

 

According to Ray, Siren is 1050 empty, 900 payload. Total 2000kg.

 

I think you've answered your own question. Among these three designs, Woods Eagle 24 does everything you want it to do and is substantially easier and cheaper to build and maintain than the other two.

I will point out that there are a lot of catamaran designs in this size range without centerline bridge deck steering stations, and there's probably good reason for that in terms of optimal use of the available space in a relatively small cruising multihull. I am happy to suggest a few designs easier and cheaper to build than even Eagle 24, some trailerable, if you'd like.

 

I think it's important to remember these are just estimates. The Siren has never been built and probably no one has weighed any of these boats. Designers uses different methodologies to arrive at estimated dry weight, so comparisons are not very meaningful. The total displacement is meaningful because that is estimated from the volume under DWL, but load capacity is not accurate because one must subtract the inaccurate dry weight from the loaded weight at DWL.

A more meaningful method to compare the carrying capacities of the boats is to add up the volume of the plywood from the materials list and multiply it by the density of the plywood you intend to use. Subtract that number from the displacement at the designed waterline and you will have a more meaningful comparison of load capacity.

There are some designers who actually use this crude methodology and admit to it. The assumption is that the plywood scrap is equal in weight to all the other components (solid wood, epoxy, paint, fittings, rig etc). Even if two designers use this same crude methodology, they may arrive at a different estimated weight because they may use a different plywood density in the calculation.

Can you share the plywood materials list for the Duo1000 and the Siren?