DIY Cruising Catamaran: Complete Building Guide
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A brand-new cruising catamaran can set you back a hefty amount of money. However, a DIY cruising catamaran provides a more affordable way to own your own boat. While building a large boat can be an extremely challenging and time-consuming experience, nothing beats the pleasure of bringing your own boat to life.
To build a DIY cruising catamaran, buy good design plans, determine your budget and find a working space. Next, choose your hull material, buy supplies and start building the mast beam. Build and sheathe the hull, install bulkheads, the interior, and finally, launch the catamaran boat.
In this article, you will find a complete guide to building your own catamaran. You will also find detailed information on why you may want to consider building your catamaran and approximately how much this project would cost. Finally, we will explore the advantages and disadvantages of building a catamaran from scratch.
Why You Might Want To Build Your Own Catamaran
Most people might think that purchasing a used boat to repair and fix it up would be cheaper than a DIY cruising catamaran. But while building your own catamaran could be an enormous undertaking, it also comes with many advantages over buying something used.
Other than the unique opportunity to create beautiful memories and experiences while cruising, sailing, and exploring beautiful coastlines, there are a number of benefits that come along with the DIY approach.
Knowing Your Boat
Building your own catamaran provides you with intimate knowledge of your boat. You will know every corner, including where to find every bolt, wire, bulkhead, rib, hose, and support as you installed them yourself. This knowledge will enhance your confidence while at sea since you will have entrusted your life to a boat whose history you are aware of and deeply connected to.
Pride of Ownership
The satisfaction you get from crafting something with your own hands is immense. As a result, the knowledge that you built your boat from scratch will fill you with absolute pride and an immense sense of achievement. Furthermore, as an owner-builder, you get to keep and enjoy the boat for as many years as you wish.
Substantial Cost Savings
Building your catamaran will work out cheaper than buying a new or even gently used boat. Though you will likely require some additional labor since doing some things will require an extra pair of hands, if you are particularly good at DIY, you will save a significant amount of money on labor costs as a whole.
Freedom To Create Your Own Designs
If you decide to buy a catamaran boat, it might not be easy to find one that meets your unique needs. However, instead of choosing from production boats that bear traditional and outdated designs, you can come up with an ultra-modern design or style for your catamaran. You also get to pick your layout, size, and equipment based on your taste and budget.
Great Learning Experience
Building your own boat will help you pick up numerous skills that will come in handy later when sailing your boat. As much as you might still require an expert to help you with specialized skills like carpentry or wiring, your new skills will serve you well. This will also be beneficial when it comes to your boat’s maintenance and fixing things for yourself.
What To Look For in Catamaran Boat Designs
When deciding on the type of catamaran boat to build, you may want to choose a design that’s simple and easy to build. This is because doing so will allow you to spend a shorter time building the boat.
You also need to have a set of requirements to guide you in choosing your design or what you might call an ideal cruising catamaran wish list. This is essential because, ultimately, you want to build a boat that offers outstanding qualities such as:
- Delivers good speed
- Affordable to own and operate
- Agile, strong, and easy to maintain
- Has a high resistance to capsizing
- Great for sailing and cruising
- Delivers a comfortable and easy motion underway
- Good handling ability and high performance under sail
- User-friendly embarking and disembarking
- Provides ample living and accommodation space
- Presents a reasonable resale value
It’s worth noting that, in general, catamaran boats tend to offer a fair resale value mainly because of scarcity and the high price accorded to production models. So, if you build a well-constructed catamaran, you are bound to get a return that’s much higher than the cost of materials upon resale.
It’s also good to consider whether the design you settle on is from an established designer. This is significant because documentation of the building process is just as valuable when it comes to selling the boat.
How Much Would It Cost To Build Your Own Catamaran?
The cost of building your cruising catamaran will depend heavily on the size of the boat you plan to build and the skills you bring to the table. To give you an idea of probable costs, a professionally built 40 foot (12.1 m) long cruising catamaran could go for up to $300,000.
Though building it yourself will undoubtedly be cheaper, most DIY boatbuilders tend to underestimate the expected costs. Your final costs should cover not only the cost of material and equipment but also the labor and time it would take to come up with the final product.
If you were to build a 40-foot (12.1-meter) catamaran, your cost of materials would range between 20-30% of the total cost. Therefore, for $300,000 total, the boat’s materials would range between $60,000 and $90,000. The hull tends to range between 15-35% of the total build. Again, this depends on the finish and furniture.
But before you even start working on the DIY project, you will need to figure out where to do the work. If your home has ample space, then you can opt for a backyard building. But if you live in a small apartment, then you might want to consider renting a small garage at first and then move on to a boatyard later. This is one of the significant costs involved in building your multi-haul.
What You Will Need
To get a clearer picture of how much the entire project would cost, let’s have a look at what else you will need to purchase.
- Good design plans
- Working space
- Ground tackle
- Matting and roving
- Equipment such as the engine, windows, rudders, deck fittings, mast, and rigging
In addition to the above, you also need to install plumbing and electricals. You may also want to consider going electric rather than using diesel. Not only will this drastically reduce your maintenance costs, but you get to use the regenerated power for all of your housing needs while sailing.
Some catamaran boat designs help you save costs by advocating the use of less expensive corpus materials. Most of the material goes directly into making the boat, which means there is hardly any wastage on vacuum bagging . With this method, there are few molds and temporal building forms and fewer fillers to grind off as waste. All these factors reduce the time and cost it takes to build your catamaran boat.
That said, building a boat of any kind is a huge financial undertaking. As such, you still need to have the financial ability to keep building; otherwise, your project will stall or take much longer than anticipated. Instead of enjoying yourself and making memories cruising to faraway lands, you might end up spending all your time building a seemingly never-ending boat.
To reiterate, this project is more of a labor of love, given that it involves a tremendous amount of manual work. Calculating an hourly rate on the time spent building the boat and adding this cost to that of materials may make it seem a very pricey exercise. However, it is vital to understand that your time matters, and every hour you spend working for “free” should be included.
With that in mind, you need to ensure that you are fully devoted to the boat construction project and are sure you want to do it before you begin. Stopping halfway because it seems like too much work would be incredibly costly.
How To Build a Catamaran
When it comes to building a cruising catamaran, you have 3 main options:
- You can buy an old boat and refurbish it.
- Purchase a bare hull plus deck molding for a home-boat building.
- Start from scratch and build everything, including the hull, on your own.
As mentioned above, renovating an existing boat may end up being more costly than starting from scratch. To build a catamaran boat from scratch, follow the below step-by-step guide.
Prepare the Essentials
Before you jump into such a large project, there are several important aspects to consider:
- Buy your plans from an established catamaran designer. You can also get inexpensive, easy-to-build catamaran designs online.
- Get access to a large working space or build a shed . Depending on your climate, you may need to opt for climate control to avoid an excess of moisture in humid areas.
- Decide on your choice of hull material. This could be fiberglass, aluminum, steel, wood, or ferroconcrete.
- Start working on a bill of materials estimate. Include everything that you think you need to get a better idea of the initial costs.
Build the Mast Beam
Using wood and epoxy, cut and glue together the pieces of wood that will form the mast beam. Most of the work at this stage can occur in a garage since it involves building small parts. Still, the work could take up to 4 months, so be prepared to put in long hours.
Build the Boat Hull
Now, it’s time to build the boat’s hull. A catamaran comprises two hulls which are connected with a deck. Below is a short video showing how to build a hull mold:
This work requires a larger facility, so you might need to move out of the garage and into a boatyard. If you don’t have access to a larger workshop, consider building a shed where you can work as you do the construction. Make sure there’s enough room to fit the boat and also allow you to work comfortably. To cover the shed, you can use opaque white tarps.
Sheathe the Hull
Get all the materials you require for this stage in the construction, such as lots of resin, fiberglass, and foam for use in the hull cores. You’ll also require matting and glass roving to sheath the hull .
Sheathing helps to make the hull impervious to water and other marine borers. But first, you need to prepare the hull using a rotary sander. To make it as smooth as possible, use light, sweeping strokes. This is a very dusty task so be prepared to wear a facemask and safety goggles.
Install the Bulkheads
Next is installing the plywood bulkheads . You might need to call in friends to help turn the hulls or use a crane. In this step, you will need to laminate the hull sides on the molded hull panels and bond them above the bulkheads. Ensure the bulkheads are snug and sealed in place.
Construct the Interior Structure
Over the next couple of months, the boat work will involve joining the hulls together with the beams that you had made back in the garage. Then, install the cuddy cabin, decks , and the cockpit . Soon the boat will start to take the shape of a catamaran.
Next, proceed to construct the major structural components such as stairs, hatches, mini-keels, and the interior. Then comes the work of fairing the boat, which is quite labor-intensive.
Finally, it’s time to apply primer on the catamaran boat and start the paintwork. Before painting the boat, you will need to do additional sanding to finish off the two layers of primer as well as fill all the pinholes. Since it’s a large boat, the catamaran has lots of surface area; thus, the sanding could get extremely exhausting—mentally and physically—at this point.
The painting can take a while, too. The hulls are the easiest to paint, but the topsides, non-skid, as well as masking and prepping could seem never-ending.
The final stretch involves working on the center bridge deck cabin and other final touches like installing the engines, electricals, and plumbing. This is also the time to fix the rudders, rigging, mast, windows, and deck fittings.
Launch Your Cruising Catamaran
After many months or years of hard work, your cruising catamaran is finally ready to test the waters. After lowering the boat into the water, check carefully in case there are leaks. If none, you can set up the sails and take your catamaran out for your first cruise.
Below is a short video that takes you through the entire boat-building process:
If you don’t have deep pockets, don’t despair. It’s also possible to build an inexpensive catamaran boat, as shown in this post from the coastal passage .
The Pros of Building a Catamaran
Though it will be a costly endeavor, there are so many things to look forward to should you decide to build your own catamaran:
- It can be lots of fun.
- You get to have a new boat.
- It’s an excellent hobby for DIY enthusiasts.
- The effort is rewarding.
- It offers a great learning experience.
- You get the exact kind of boat you want.
- You can alter building plans and tailor the boat to suit your specific needs.
- It might be cheaper than buying a new boat.
The Cons of Building a Catamaran
Though there are a number of positive aspects to a DIY build, it is just as important to keep in mind that it won’t always be easy:
- Maintenance costs can be quite high.
- It’s both mentally and physically exhausting.
- It might require some technical know-how.
- It can take many months or even years to complete.
- It requires a lot of commitment to finish the DIY project.
- It might be challenging as well as expensive to get insurance.
- You will spend almost all your free time building the boat.
DIY Cruising Catamaran Tips and Tricks
If you are new to boat building, it would be a good idea to build a small boat first. This would give you a good indication as to whether you’d enjoy tackling a more extensive project like building a catamaran. Again, if you are the handy type, fixing your own electronics could also save you a significant amount of money.
Here are more tips and tricks to get the most out of your DIY cruising catamaran:
- Lower your costs. Bring down your costs even further by sourcing for parts and supplies at marine surplus outlets, Craigslist, eBay, or wholesale suppliers.
- Enhance your resale value. Most home-built boats are not easy to sell since they tend to be too customized. To enhance your resale value, it’s advisable to work with a standard design from a well-established naval architect.
- Follow the design instructions. Make sure to follow the designer’s instructions regarding the type of materials and tools to use during the build to avoid making costly mistakes.
- Maintain your original budget. Avoid any additional customizations once you have started building the boat. Using good plans and sticking to them ensures that your budget doesn’t spiral out of control.
Final Thoughts
Building a catamaran is about more than saving money. It’s fun, exciting, fulfilling, and can be a great learning experience. While it might take many months of back-breaking work, comparative shopping and sourcing for materials will help you save a lot of money. Still, at the end of it all, you’ll have a beautiful catamaran boat, all ready for your first cruising adventure.
However, if you have neither the time nor the energy to build your own catamaran from scratch, refurbishing an existing hull might prove faster and easier. It also works out much cheaper than buying a new boat.
Owner of CatamaranFreedom.com. A minimalist that has lived in a caravan in Sweden, 35ft Monohull in the Bahamas, and right now in his self-built Van. He just started the next adventure, to circumnavigate the world on a Catamaran!
One thought on “ DIY Cruising Catamaran: Complete Building Guide ”
Hello, I am a French Quebecer who is original, imaginative, creative and who finds that all boats and catamarans have a huge flaw and a very big lack of logic. I would have a brand new concept…. I am sending this message to any catamaran creator – designer to make those who have the opportunity and the intelligence to want to know about my innovative idea which will finally upset the market much richer. An idea that will totally change the concept of sailing, navigation and save so much worry!! All I would ask for is a small percentage of each sale of the new product. To be able to make me produce one when I have enough!! It is certain that like that, you just want to tell me: come on Mr. Lessard give us your idea but do not take your word to help me in return! But, if you are the kind of man to have only one word and maybe have a proof of your good faith if the realization of the project would make it… I will be very happy!! Giving it to everyone wouldn’t bother me either…. all I would like is to be able to find flax fiber (too expensive carbon) to be able to try to make my catamaran myself. Because not rich! Have a nice day and looking forward to having a message!!
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Catamarans and Trimarans
Catamaran and Trimaran Boat Plans make it a reality to build your own catamaran or trimaran. Multi-hulled sailing vessels are a special class of boat. A very different mind set is required when thinking about sailing a multi hull, let alone getting your head around building one.
There are some unique challenges building a multi-hull sail boat, the extra beam added by each hull for instance can create storage issues while under construction. Hartley boat plans make the build process straight forward for even amateur builders. However with all things considered, building a multi can be an amazing journey.
Fast Twin Catermaran
Lively 28 Cruising Trimaran
Lively 35 Cruising Trimaran
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Plans and Kits for Catamarans and Proas and other Multihulls
Check out my page on Advantages and disadvantages of multihulls
If you're planning a boatbuilding project you might like to check my boatbuilding resources. These are articles from my website and some outside links and build diaries.
Multihull plans in no particular order
Email me if a link is broken or if I've missed a boat. I try to keep my links good but things change quickly on the web.
I try to include most plans that I run across. I only exclude the ones that seem to be dubious, some are plagiarized or some just seem to be of terrible quality, or a website that includes pop-ups or other nasty things, that I don't dare include them. I have not personally checked all plans. Before building, do your homework.
- Bruce Roberts has aluminium and fiberglass boat plans for large Catamarans
- Schionning Designs has plans and kits for Cats, Trimarans and a keelboat.
- From Wooden Boat Magazine plans for a 20 ft Trimaran. Also a Sailing Outrigger Canoe
- Kurt Hughes has both large and small Catamarans and Trimaran plans.
- Sailing Catamarans has beach cats.
- Woods Designs has small and large boat plans
- K-Designs has Little Tri sailing trimeran dinghy and others.
- Dudley Dix Yacht Design has a large cruising catamaran
- Svenson's Free Boat PLans has an old Mechanix Illustrated Hobby Kat plans along with many other boat plans
- Duckworks Magazine has a whole section of small sailing multihulls.
- James Wharram Designs offers plans and will build also.
- Tornado Building Plans free from The Beachcats.com
- Hartley Boats has a few designs for sailing cats.
- Applegate Boatworks has plans for Blue Joseph, a proa
- Glen L Offers plans for La Chatte, sailing Cat.
- Scarab Folding Trimaran Dinghy.
- Selway Fisher has a design for simple Catamarans.
- Slider Cat Ray Aldridge design from Duckworks
- Gary Dierking is well known in the Proa community.
- Chesapeake Light Craft has many designs, well thought out plans and kits. This is Junior outrigger.
- Also from CLC 2 large proas Madness, and Mbuli
- Novacat 17 Plans and build photo IN German, get mr. Google to translate.
- From Svenson's popular mechanix plans Cats Paw free plans
- Fyne Boat Kits has several multihull designs. He also offers add-on outrigger for canoes and kayaks.
- Instructable for a Polytarp Crab Claw sail for a proa
- A one day proa project Maybe not quite perfect but worth looking at. Here's another instructable sailing outrigger canoe
- Angus Rowboats has a sailing conversion plan with outriggers.
Too Much Choice
There are a great number of large cruising catamaran and other multihull plans out there. I think one of the reason is that building a large catamaran is easier than building a cruising size keelboat. Many designers feel confident that the home builder has a good chance of success in putting together quite a competent multihull.
I have not included all the large multihull plans and kits I have found, nor have I included many of the home made single effort catamarans that are out there.
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- Skerry from plans
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I try to be accurate and check my information, but mistakes happen. ALSO keep in mind that not all boat plans are well designed. Old Banks Dories are particularly tricky because they were notoriously unsteady until they had some weight in them. Check the boat forums, many people have built dories. I have not built these boats and I can't recommend or proscribe any.
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Catamaran Hull Design
- Post author By Rick
- Post date June 29, 2010
- 2 Comments on Catamaran Hull Design
Part 1: Notes from Richard Woods
Since the America’s Cup experimented with going multihull, there’s been a lot of interest in catamaran performance and the catamaran hull designs that define performance. Many guys are investigating whether to buy a catamaran or design and build their dream boat. Let it be said here that building a large catamaran is not for the faint of heart. People begin building 100s of boats a year, yet few are ever completed, as life always seems to have a way of interfering with a good boat build.
Never the less, since the rest of this website is about selecting and buying a boat , it only seems fair to have at least one webpage that covers catamaran design. This page contains notes on boat hull design goals and an accompanying page from Terho Halme has mathematical formulas used in actual catamaran hull design. It has become a popular research stop and an important reference to the catamaran design community.
The content of this page was reproduced from the maestro of Catamaran designs, renown British naval architect, Richard Woods, who not only designs catamarans, he sails them across oceans…. repeatedly. He has a lot to say on the subject of catamaran hull design.
“…When it’ all said and done, the performance of a sailing catamaran is dependent on three primary specs: length, sail area and weight. If the boat is longer it generally means it’ a faster boat. If she has more sail area, it means she’ a faster boat and if she’ light it means she’ a faster boat. Of course, there are limits: Too much sail area capsizes the boat in brisk winds. If the boat is designed too light, she will not take any kind of punishment. Too slim a hull design and the boat becomes a large Hobie Cat capable of only carrying your lunch. Of course, too long and large and you’d have to be Bill Gates to afford one. Then there are lot of additional and very important factors like underwater hull shape, aspect ratios of boards and sails, wet deck clearance, rotating or fixed rigging and so on….” Richard Woods
All Catamarans are not equal, but all sailboats have two things in common: They travel on water and they’re wind powered, so the Catamaran design equations in the 2nd part should apply to every catamaran from a heavy cruising Cat to a true ocean racer.
Richard Wood’s comments on catamaran design:
We all know that multihulls can be made faster by making them longer or lighter or by adding more sail. Those factors are the most important and why they are used as the basis of most rating rules. However using just those figures is a bit like determining a cars performance just by its hp and curbside weight. It would also imply that a Tornado would sail as fast forwards as backwards (OK, I know I just wrote that a Catalac went faster backwards than forwards)
So what next?? Weight and length can be combined into the Slenderness Ratio (SLR). But since most multihulls have similar Depth/WL beam ratios you can pretty much say the SLR equates to the LWL/BWL ratio. Typically this will be 8-10:1 for a slow cruising catamaran (or the main hull of most trimarans), 12-14:1 for a performance cruiser and 20:1 for an extreme racer.
So by and large faster boats have finer hulls. But the wetted surface area (WSA) increases proportionately as fineness increases (for a given displacement the half orange shape gives the least WSA) so fine hulls tend to be slower in low wind speeds.
The most important catamaran design hull shape factor, is the Prismatic Coefficient (Cp). This is a measure of the fullness of the ends of the hull. Instinctively you might think that fine ends would be faster as they would “cut through the water better”. But in fact you want a high Cp for high speeds. However everything is interrelated. If you have fine hulls you can use a lower Cp. Most monohulls have a Cp of 0.55- 0.57. And that is about right for displacement speeds.
However the key to Catamaran design is you need a higher Cp if you want to sail fast. So a multihull should be at least 0.61 and a heavy displacement multihull a bit higher still. It is difficult to get much over 0.67 without a very distorted hull shape or one with excessive WSA. So all multihulls should have a Cp between 0.61 and 0.65. None of this is very special or new. It has been well known by naval architects for at least 50 years.
There are various ways of achieving a high Cp. You could fit bulb bows (as Lock Crowther did). Note this bow is a bit different from those seen on ships (which work at very specific hull speeds – which are very low for their LOA). But one problem with them is that these tend to slam in a seaway.
Another way is to have a very wide planing aft section. But that can increase WSA and leads to other problems I’ll mention in a minute. Finally you can flatten out the hull rocker (the keel shape seen from the side) and add a bustle aft. That is the approach I use, in part because that adds displacement aft, just where it is most needed.
I agree that a high Cp increases drag at low speeds. But at speeds over hull speed drag decreases dramatically on a high Cp boat relative to one with a low Cp. With the correct Cp drag can be reduced by over 10%. In other words you will go 10% faster (and that is a lot!) in the same wind and with the same sails as a boat with a unfavorable Cp. In light winds it is easy to overcome the extra drag because you have lots of stability and so can fly extra light weather sails.
The time you really need a high Cp boat is when beating to windward in a big sea. Then you don’t have the stability and really want to get to your destination fast. At least I do, I don’t mind slowly drifting along in a calm. But I hate “windward bashing”
But when you sail to windward the boat pitches. The sea isn’t like a test tank or a computer program. And here I agree with Evan. Immersed transoms will slow you down (that is why I use a narrower transom than most designers).
I also agree with Evan (and why not, he knows more about Volvo 60 design than nearly anyone else on the planet) in that I don’t think you should compare a catamaran hull to a monohull, even a racing one. Why chose a Volvo 60/Vendee boat with an immersed transom? Why not chose a 60ft Americas Cup boat with a narrow out of the water transom??
To be honest I haven’t use Michelet so cannot really comment. But I have tested model catamarans in a big test tank and I know how inaccurate tank test results can be. I cannot believe that a computer program will be better.
It would be easy to prove one way or the other though. A catamaran hull is much like a frigate hull (similar SLR, L/B ratios and Froude numbers) and there is plenty of data available for those. There is also a lot of data for the round bilge narrow non planing motorboats popular in the 1930’-50’s which again are similar to a single multihull hull.
One of the key findings I discovered with my tank test work was just how great the drag was due to wave interference between the hulls. Even a catamaran with a modern wide hull spacing had a drag increase of up to 20 % when compared to hulls at infinite spacing. One reason why just flying a hull is fast (the Cp increases when you do as well, which also helps). So you cannot just double the drag of a single hull and expect to get accurate results. And any speed prediction formula must include a windage factor if it is to give meaningful results.About 25 years ago we sailed two identical 24ft Striders next to each other. They were the same speed. Then we moved the crew of one boat to the bow. That boat IMMEDIATELY went ½ knot faster. That is why I now arrange the deck layout of my racing boats so that the crew can stay in front of the mast at all times, even when tacking or using the spinnaker.
I once raced against a bridge deck cabin catamaran whose skipper kept the 5 crew on the forward netting beam the whole race. He won.
Richard Woods of Woods Designs www.sailingcatamarans.com
- Tags Buying Advice , Catamaran Designers
Owner of a Catalac 8M and Catamaransite webmaster.
2 replies on “Catamaran Hull Design”
I totally agree with what you say. But Uli only talk sailing catamarans.
If only solar power. You need the very best. As limited watts. Hp.
The closer to 1-20 the better.
Closing the hulls to fit in cheaper marina berth. ?
You say not too close. But is that for sailing only.
Any comment is greatly appreciated
Kind regards Jeppe
Superb article
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Coral Sea 25 by Mike Waller Yacht Design
25 ft plywood 'v' hull low cost cruising catamaran.
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| Hull construction | Plywood | |
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URL: http://wallerdesign.com.au/cs25.html
Description:
The CORAL SEA 25 CATAMARAN is designed specifically for the builder who wants the maximum boat for minimum cost and building time. To this end the vessel features seperate hulls connected by strongly mounted cross beams.
The vessel is demountable for trailing and employs a simple, easily built, trunkated 'V' hull shape. The trunkated 'V', is as simple to build as the straight 'V', but has better sailing characteristics, such as less wetted surface, better tacking etc. This yacht is definitely a case of the most boat for the least work and cost.
The Coral Sea 25 is designed for safe, comfortable family sailing, with bunks for 4 in 2 seperate hulls. It also has a room for a portable toilet, small cabin lockers, and a huge cockpit for socializing. There is good sitting headroom in the hulls.
For simplicity and ease of construction the hulls consist of a plywood shell wrapped around a framework of plywood bulkheads and timber stringers. This is still the easiest way to construct a timber boat, and when combined with timber / epoxy construction, is a very cost effective way to build a sound vessel.
The rig is a simple but efficient ¾ sloop, with a large sail area for light weather cruising, easily reefed in heavier winds. The rigidly mounted beams allow the vessel to carry an efficent rig which can stand up to the weather. The rigging is as simple as possible, and is based on the KISS principle. Two separate rigs are available, a standard rig for offshore and open water sailing, and a larger inshore rig. The choice is at the builders discretion.
Auxiliary power is from an outboard in a separate pod beneath the cockpit footwell. The vessel features small skeg keels for cruising simplicity, and efficient transom hung rudders for positive helm control. Steering as designed is by tiller. The Coral Sea 25 is an easily constructed vessel capable of providing it's owners with years of comfortable and fun cruising, or even ocean voyages for the more skillful and adventurous sailors.
| Design | Length | Beam | Sail area | Engine power | Compare | |
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| by Mike Waller Yacht Design (35 ft plywood 'V' hull low cost cruising catamaran | | | | - | ||
Catamarans about same size as Coral Sea 25
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If you have fine hulls you can use a lower Cp. Most monohulls have a Cp of 0.55- 0.57. And that is about right for displacement speeds. However the key to Catamaran design is you need a higher Cp if you want to sail fast. So a multihull should be at least 0.61 and a heavy displacement multihull a bit higher still.
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Description: The CORAL SEA 25 CATAMARAN is designed specifically for the builder who wants the maximum boat for minimum cost and building time. To this end the vessel features seperate hulls connected by strongly mounted cross beams. The vessel is demountable for trailing and employs a simple, easily built, trunkated 'V' hull shape.
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