The Outboard version of the 29z can handle up to twin 250-hp four-strokes on a bracket. Efficiency is less than with single diesel power – the builder claims about 1.7 nmpg. The MJM 29z OB can run over 50 knots, says MJM, and the 29z draws just 16" with the motors tipped up.

Light Makes Right

One of MJM’s founding fathers is Bob Johnstone, the eminence grise of J Boats, one of the world's most successful sailboat builders. When developing the MJM 29z, and other boats in the MJM stable, Johnstone and designer Doug Zurn applied the light-is-right philosophy of sailboat building to powerboats. Less weight means less power is required, and less fuel is burned, to meet performance goals. Taken from another angle, lighter weight results in more speed with equal horsepower.



The Downeast version encloses the pilot area with StrataGlass side windows that roll up for fresh air, roll down to make the space cozy. All three versions have similar cockpit layouts and belowdecks accommodations.

The MJM 29z weighs about a third less than comparably sized boats; the single 300-hp Volvo Penta D4 diesel sterndrive in the Express and Downeast versions cranks out 30+ knots of top speed, according to the builder, and cruises at 25 knots and 3 nmpg we're told. Her length-to-beam ratio of more than 3:1, coupled with sharp forward sections and lots of bow flare, make for a smooth, dry ride in choppy water and an easy transition between semi-displacement and planing speeds.



She's a sterndrive boat, but you won't know it by looking: when she is in the water, the swim platform hides the Volvo Penta Duoprop drive and keeps the Downeast's profile traditional right to her transom. A narrow beam combines with 17 degrees of deadrise aft to produce efficient fuel consumption.

Built to Rigorous Standards

The MJM 29z exceeds ISO structural standards for small craft of its size, we’re told by the builder. These are tough requirements based on nasty conditions typically encountered in the waters around northern Europe. She is built to meet ISO Category A, Ocean, certification, but classed in Category B, Offshore, because of her size, says MJM.

Boston BoatWorks, builder of all MJM yachts, adds Kevlar to the hull for strength, and abrasion and puncture resistance. The boat is laminated with durable epoxy resin, which is unusual in powerboat building because it is far more expensive than conventional laminates of vinylester and polyester resin that most builders use.

Core Cell foam coring is used in the hull and Airex foam is used in the deck. Balsa core is more resistant to impact than is foam, e.g, from dropping a loaded cooler onto the deck, and that is why it is used in the cockpit. The 29z’s bottom is solid epoxy, E-glass and Kevlar laminate along the keel and chines, and it is supported by a reinforced structural grid. The hull is vacuum-bagged to ensure the ideal epoxy resin-to-glass ratio, then baked in an oven for 48 hours to fully cure the laminate.

This is about as hi-tech a hull construction regimen as we know of in the powerboat industry and it allows MJM Yachts to achieve an exceeding light hull.



The custom Armstrong bracket on the OB version can hold up to twin 250-hp four-strokes. For those who want to go really fast, we recommend the outboard version of the 29z.

Green is Good

MJM is proud of the fact that Boston BoatWorks' hi-tech practices have less impact on the environment than typical open-mold hull building. Making the best use of materials means using less of them, and consequently a reduced carbon footprint. Epoxy resin is "greener" to produce than poly- or vinylester, and releases no VOCs (volatile organic compounds) even during open cure. Boston BoatWorks uses closed-molding techniques to further ensure zero emissions, an important consideration in 21st century boatbuilding.



The cabin layout includes "U"-shaped seating that converts to berths, enclosed head and a basic galley. Headroom is 6'. The Corian sink cover creates extra counter space, valuable in a boat like this, where most food preparation will involve making sandwiches for lunch. Joinery is satin-finished cherry, with a teak-and-holly sole optional.

Performance

The biggest impact on the environment isn't when a boat is built – it's when the engine is started. Keeping the MJM 29z lightweight and energy-efficient reduces the amount of fuel burned, and therefore the amount of greenhouse-gas emissions. According to MJM (we haven't tested the boat ourselves), the diesel-powered 29z gets about 3 nmpg at 25 knots.



The helm is minimalist, but has room for everything that's needed, including a large multi-function display. A companion swivel seat is to port.

Top speed is about 31 knots, according to MJM, with the standard 260-hp Volvo Penta D4 Duoprop; it comes with electronic controls. A 300-hp D4 is optional.



We like this cockpit layout, with a padded motor box (also makes maintenance easier) and transom door. A full wraparound seat is standard. Upholstery is synthetic leather.

Recommendation

We like burning less fuel, but economy alone isn't enough to make us recommend a boat; she has to light our fire in other ways, too. We like how the MJM 29z Downeast is built, we like her lines and her traditional finish belowdecks. We like the option of several cockpit layouts, including one with an open cockpit, transom door and a padded engine box instead of wraparound seating with the engine hidden underneath.



If you want outboards, MJM will set up your 29z like this, with a custom Armstrong bracket and with (or without) the full-beam Adirondack seat. We're not crazy about the wooden back, and why buy this boat with outboards and lose the economy of diesel? Because the OB version will run faster than 50 knots, according to her builder!

We estimate you'll spend around $375,000 for a well-equipped sterndrive 29z, one with a bow thruster, A/C, shore power, all-electric galley, trim tabs, TV, electronics and maybe a genset. If you're looking for just a dayboat, you won't need some of these options; being able to rig the boat just how you want her is a big plus for us.

We recommend taking a look at the MJM 29z if you can afford the price of entry, especially if you're green-minded and you appreciate the very best in lightweight fiberglass boat construction with an interior that has a salty, yacht-like feel.