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The Chat 18 is a safe day sailing catamaran designed for sheltered waters and is very simple and easy to sail. Even so, it is still a fun and responsive boat.

Comprehensive building plans cost GBP140 

Please click on the button below if you wish to buy plans. Note: You can pay using Paypal or with your normal credit card. 

Plans will be sent as a zip file of pdfs once payment has been received. This is no longer an automated system, so please allow 48 hours for your order to be processed and your plans emailed to you. If you have not received plans after that time please contact us at This email address is being protected from spambots. You need JavaScript enabled to view it.  

 Kits will be available shortly from my US and UK dealers. 

The builder commented "Thank you very much for the perfect plans! I can't imagine how you do it, everything comes very nice together, resulting in a boat that is, in my opinion, both good looking and very useful for daysailing. 

As you can tell by the pictures, she is quite high on the water. 

Later: "Two and a half months ago our Chat 18 went into water, after six months of building, from buying plans to launching. How's it gone since then?

It's going very well! if there is just a bit of wind (Bf 3), it sails like a tierelier (an un-translatable Dutch word that Wikipedia defines as "expresses that something is going fast and / or well"). No problem tacking at all.

The cockpit and benches are wonderfully spacious and that is really nice during sailing. We have never been so comfortable on a boat. It's also nice that we can easily put our bags and cooler in the cabin.

Was it worth it? A winter long evening in a cold and damp party tent to build a catamaran of 5.60 x 2.50 m? Measuring, drawing, sawing, sanding, filling, painting and filling again ... Yes, it was worth it. We have never been on our boat as much as this summer. Just be nice outside for a trip or relaxing. The nice weather also helps. We gladly pack the cooler and invite children or friends.

The Chat 18 meets the original wish. It is a pleasant day sailor, which is very stable on the water for such a small sailboat. And that was a condition for Hanny to have fun sailing."

Note this boat has a used beachcat rig rather than the gunter rig that was designed. Photos below show it being built and are taken from the blog, see below.

You can download a provisional studyplan HERE and see a great builders blog here

http://projectcatamaranchat18.blogspot.co.uk/

Please email me This email address is being protected from spambots. You need JavaScript enabled to view it. for a free full study pack including sample build sheets

It is 8ft wide so is easy to trail with no assembly needed. Indeed it will be quicker than most small monohulls to get from trailer to water, typically 15 minutes. That's because raising the mast is quick and easy, there is no keel to lower or water ballast to fill. Furthermore, the boat is a rectangular platform, safe and easy to walk around on when onshore while most of the gear and the sails can be left in place when trailering. The trailer itself is just a regular flat bed trailer, no supports or rollers are needed.

The small cuddy offers enough space for simple cooking, with icebox stowage, and privacy for a porta potti. The cockpit seats are 2m (6ft6in) long so the integral boom tent means it is quite feasible for two people to camp on board.

The rig features a gunter mast so it can be easily home built in wood using the standard "birds mouth" construction. The gunter rig also keeps the spars short to simplify trailing and rigging. Of course a conventional one piece mast can also be used, maybe an old beach cat rig?

The two full length battens increase both mainsail area and efficiency and allow the leech to twist off in wind gusts, while the "soft" lower part is easier to "read" and reduces rig weight and cost compared to a full battened sail.

The engine fits in a nacelle for easy access and to increase manouverability. A 2.5hp outboard (or maybe a yuloh) is suggested for sailing, but up to 20 hp is possible when using the Chat18 as a motor sailer with speeds around 10 knots

The Chat 18 is fitted with low aspect ratio keels for simplicity of both building and sailing, however daggerboards are an option for very shallow water sailing. The rudders are offset to increase the width of the transom boarding steps.

The high freeboard, plus the protection that the cuddy provides, helps keep crew and passengers dry. The hulls have extra buoyancy aft to support crew weight (many small catamarans trim by the stern with crew on board). The bridgedeck clearance is kept as high as possible and it is "Veed" for extra stiffness and to reduce wave slap.

Despite its small size and the essential watertight compartments, there is still lots of storage space in the hulls for anchor, warps, fenders, deck cushions, BBQ, fishing tackle and all the other "stuff" that makes a day out on the water more enjoyable.

The Chat 18 is very simple to build, featuring all flat panel plywood with glass/epoxy chine joints so there is no timber bevelling. It is small enough to build in a double garage using "hardware store" materials and minimal tools, thus making it an ideal first boat project.

Latest News August 2020 

Erik's home built Chat 18 catamaran has just celebrated its second birthday! Erik reports:

"We are still sailing, and very much enjoying the boat! I've had a new mainsail made, which made a huge difference. See the picture of the sail, the boat is noticeably faster. Last season I also bought a custom made cockpit tent. A lot of room inside and also less water in the cockpit.

So I am still very happy with the boat. It sails very well , and the speeds quite good for it's length (similar to the speed of a Valk, which is 1 meter longer).

Chat is a very comfortable alternative to the more usual open boats that are sailing on the lakes. Much more space in the cockpit, it stays comfortably upright, making the crew less nervous in a gust (which my wife highly appreciates), and there is space for shelter in the small cabin."

Please contact me for more details on the plans and kits. The former are available now, the latter has been delayed by covid, but they should be available by early 2021 in the UK.

I decided that a Chat 18 would be a fun boat for my wife and I to sail in the Plymouth area. So we had one built over the winter and launched it in late April 2021. Delayed because of covid lockdowns.

Photos show me on the first real sail. In 12 knots of wind top speed was 9.5 knots and 5.5 knots upwind. Very easy to manouver, fingertip steering, even at speed, and tacks easily from reach to reach.

As you can see, I am also using a cut down beach cat rig rather than the gunter rig shown on the plans. 

I have made a number of videos of our own Chat, which you can see here https://www.youtube.com/playlist?list=PLT7PbPvOm8lyerft0XzheKfQpZdcVZk2N

The Chat 18 was, in part, designed to appeal to those who, quite literally, want to chat as they sail along. So a sort of party boat under sail. 

Now that I have my own Chat I realise it may have greater performance than some would wish. I know I have a beach cat rig which is more efficient than the gunter rig I drew, but even so some may find the standard rig more than they want

Accordingly I have now drawn a smaller rig for those who are new to sailing, or who are less active, or even those who just want to chat!

Basic Materials List (approx, no allowance for waste or errors)

6mm ply 20 sheets
9mm ply 4 sheets

Timber
2in x 1in 50m
3in x 1in 2m
2in x 2in 5m
1.5in x 1in 50m (can be 3in x 1in ripped in half)
keels 1850 x 300 x 4off (laminate as necessary)
Beams 4in x 2in  x 2.5m 5 off
Rudders 3m x 8in x 1in 2 1.5in x 2m
glass tape 150m 100mm (4in) wide
Sheathing (optional) 60sqm 200g/sqm (4oz)
epoxy 40kgs (polyurethane glue optional on deck stringers etc)
screws 1000 18mm (3/4in) x no6 200 25mm (1in) x no6  st steel cs
paint, filler etc as required

Please also see my FAQs pages regarding timbers, plywood and what Planed All Round (PAR) means

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