M.B. Marsh Design offers a steadily growing range of plans for small watercraft. Our services include custom design, refit planning, condition surveys, failure analysis, systems integration and more.

Our designs hit what we think is an ideal balance between performance, capabilities, cost and ease of construction. Most of them are suitable for amateur or advanced amateur construction. These are boats that you can build in your garage, needing only patience, common tools, basic carpentry and fibreglass skills, and a willingness to learn. The resulting vessels are stylish, capable boats that will serve you well for many years.


From The Drawing Board

New designs from our drawing board, and assorted thoughts on boat design in general.

New design: Something whimsical for creative kids

Here's a new design from our drawing boards that a few of you might find interesting.

She may look a little weird there, but read on and you'll see...

Do fibreglass and carbon fibre mix?

"Let's put carbon fibre in there," says the marketing director. "That stuff's stronger. And I can sell it as a high-end feature."

"Yup, yup," replies the shop foreman. "We can do that. It's a bit pricey though, maybe we could use just a bit of it mixed with the fibreglass."

Fast forward three years, and both men are scratching their heads over why the component- which was, according to the designer, more than strong enough in fibreglass alone- has failed catastrophically even though they added a "better" material.

TL;DR: Mixing different fibres in the same load path can lead to a component being weaker than it would be if only one type of fibre had been used.

Composite chainplates: The ideal solution for composite hulls

Sometimes, old ways of doing things survive simply because "that's how it's always been".

From time to time, though, it is useful to look at the old ways to see if, in the context of modern knowledge, they still make sense. If they don't, perhaps they should be changed. In today's article, I'd like to take a look at a key component of many sailing yachts- the chainplate. Current chainplate designs date back to before the Industrial Revolution, and I think they're overdue for a redesign.

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In The Shop

Dispatches from the shop: Progress reports on our boat building projects, plus some useful information for those of you who are building, restoring or repairing your own boats.

A simple trailer tongue extension

Folding trailer tongues are nice, but a folding mechanism is expensive and hard to retrofit to an existing trailer.

With the local water levels already low and going lower, the time was right for us to modify Sunset Chaser's trailer for shallower ramps. Here's how we did it.

Crossbeam webs

After a (rather too long) hiatus from building the Starwind 860, we're back at it with the plywood webs of the aft crossbeams. (A similar set for the front crossbeams will be built once this pair are complete.)

The trimaran's folding crossbeams are a fairly conventional box section structure, with plywood webs fore and aft joining thicker top and bottom flanges of laminated wood strips.

A truckload of plywood

Delivery day is always a good day for someone building a boat.

We picked up the first batch of okoume plywood for our Starwind 860 yesterday- the first real "work trip" for the '05 GMC Yukon XL that'll eventually become this boat's road-going companion. Progress then ground to an immediate halt. (If it's 28 C and mostly sunny, you don't work- you take the boat out to the sandbar to chill out for a while.)

Learning to arc weld

One thing I never really got around to learning in high school or in university was how to do a decent job with an arc welder. It's about time to change that- Sunset Chaser's trailer needs work, our weird new Starwind 860 will need a custom trailer, and there's always plenty of stuff that needs fixing.

It's one thing to read about how to do it- friendly old Google offers up 1.58 million pages on the subject. And, having been through engineering school, I have a pretty good idea how a weld works, what a good one should look like, and how the stresses are transferred across it.

Friends who know, though, always respond with "Well, you can read all you want, but the only real way to learn it is to lay down dozens of really bad welds until you start to get the hang of it."

So, for anyone else who's thinking of learning how to weld and is a bit intimidated by the idea, here's my "Day 1" report- complete with terrifying photos of beginner screw-ups.

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