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.

Sailboat rigging costs scale disproportionately with size

Submitted by Matthew on

Size can be deceptive, particularly where a boat's purchase and operating costs are concerned.

Let's consider the cost of a sailboat's rig. We'll assume that the annual cost of maintaining and repairing the rig is a fixed fraction of the cost of building the rig in the first place, and this fraction does not change with size- an assumption, yes, but likely a reasonable one for yachts of typical design and modest size.

TL;DR: The rate at which you spend money on a sailboat's rig increases faster than the increase in boat size. This expenditure can be minimized by designing long, slender, efficient hulls that can be driven to good average speeds with relatively small rigs compared to shorter, fatter boats of the same size.

Late-night inspirations

Submitted by Matthew on

Sometimes it's fun to get a bit carried away with design work. Even if it does cut into sleep a bit.

Assessing crew risks on a powerboat

Submitted by Matthew on

Should you require all crew on your boat to wear lifejackets? If so, under what conditions? Should you restrict access to some parts of the vessel when underway? Should those rules change in different weather conditions, or with different kinds of boat traffic nearby?

I suspect that many skippers make these decisions based on gut feeling and on who they side with in bar or forum arguments. Frankly, I don't think that's the best way to make critical safety decisions.

Risk assessment is a very well-developed art. Not every decision calls for a formal risk assessment, but putting a bit of logical thought into your key safety policies is certainly a prudent idea. Today, I present an informal walk-through of this process for the Starwind 860 trimaran we're currently building.

Stretching out a powerboat

Submitted by Matthew on

Design ideas tend to build up around here faster than they can be written down. At the moment, there are seven boats on the board:

  • The Starwind 860 is under construction and her detail drawings are still being finished up.

  • The Bonaventure 570's construction drawings are in work.

  • An up-sized Almaguin (5.8 m) is awaiting final construction drawings.

  • The four Awenda planing-hull designs are on the back burner, waiting for a calm spell.

And after John Harries' post this morning on why long thin boats are cool, I couldn't resist pulling out the CAD models of the Bonaventure 1180 for a bit more detailing.

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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.

Making the best of mediocre wood

Submitted by Matthew on

Boatbuilders like to have really good wood. The best stuff is quarter sawn, vertical grain, air dried two years, felled by ceremonial beaver at midnight under a full moon.

What you actually get, especially when buying in small quantities from lumberyards that are unfamiliar with boatbuilding, is plain sawn, a bit warped, and often a bit wet, like the batch of western red cedar I'm using for various small parts of the Starwind 860 power trimaran.

Outrigger struts for the Starwind 860

Submitted by Matthew on

It's time for another boat parts update! The only way this project is going to make it to completion is if a little bit of work gets done at every possible opportunity. So, slipping in a task or two a day, we are making slow but steady progress on the Starwind 860 trimaran.

The struts that link the 860's crossbeams to her main hull have aluminum end sleeves and a red oak core.

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