PassageMaker - April 2010

Sunlight slanted in through the rolled-down Strataglass windows that formed the side and rear walls of the pilothouse, and we were having a pleasant conversation as the 40z made short work of the 1-foot chop stirred up by a light northwesterly. The aft door was rolled up for ventilation, but we weren’t shouting—rather, we were talking in fairly normal tones, even as the twin Volvo Penta IPS drives pulled us on at about 17 knots.

I turned on my sound meter, walked forward, and read 71dBA at the helm and about 73dBA in the seating area where we lounged, aft of the helm. Mary noted this and told me that one of the things she enjoys about running the 40z is that the engines are located well aft. In combination with the engine compartment sound-attenuation features and the underwater exhaust of the IPS drive system, this helps keep transferred motor noise to a minimum.

“Instead of conventional building methods, he wanted
a superior build, using materials above the norm, which
proved to be a driving force behind the selection of
the builder.”
Not long after they finalized the profile, arrangement,
and specs, Zurn and Johnstone traveled from Canada
to North Carolina to interview six yards, most of which
were custom sailboat builders well known for building
yachts using the latest technology to produce high
quality vessels. In the end, Bob selected Boston
BoatWorks, founded by Mark Lindsay and Scott
Smith. Mark Lindsay had a reputation as a builder
who looks at things from a different perspective and
finds solutions to create a better build.

Starting at the transom, the deadrise is 18. 5 degrees, hinting at a typical modified V that will stand up to rough water running at higher cruising speeds. The

Left: Doug Zurn’s MJM 40z hull design cruises efficiently at speeds from 9 to 30 knots, across a wide range of conditions. Right: Bob and Mary Johnstone cruised the Volvo Penta IPS-drive-equipped 40z from Florida to the Chesapeake last year.

THE DESIGN

Zurn Yacht Design has always been known for boats that stand out in a crowd, visually as well as under way. All of the MJM designs share Zurn’s distinctive Downeast look, with a nice reversed sheer, tumblehome sides aft, and a hard top that derives from workboats throughout Maine. There is an express version of each model, with side windows that extend from the outside front windshield pillars in a downward-sloping curve, reminiscent of Downeast bass boats.

“From the beginning, Bob wanted a better powerboat than what was already on the market,” said Zurn.

bottom shape maintains a constant deadrise for the aft third of the hull, then forms a keel, with deadrise increasing going forward in an inverted bell shape to a sharp, deep forefoot. There is plenty of flare and volume forward for reserve buoyancy and spacious interior accommodations. Each side has a lifting strake for efficiency and a chine that is of moderate width and flat aft, with a bit of reverse forward to help deflect spray.