Greenline 33

Author: Roger McAfee

Boat tests almost always require the tester to compare some aspects of the vessel being tested against other vessels in the same category. The problem testing the Greenline 33 is that there is, at present, no other regular production hybrid boat on the market — except other Greenlines — with which one can draw comparisons.

So when faced with this problem, a prudent tester asks two questions: How does the boat operate doing “normal boat” things, and how well does it do “hybrid” things? In the latter category, we look at factors such as cost, battery life, recharge rate and range under electric power, and the ease with which the electronic control system seamlessly switches from battery to traditional combustion-engine drive.

Greenline is owned by Seaway, a 30-year-old marine design, engineering, tooling and prototyping company in Slovenia but with worldwide representation in 42 countries. Seaway designs and/or engineering have been used by many of the world’s largest boat builders, including Brunswick, Beneteau, Jeanneau, Prestige, Sea Ray, Bavaria and Dufor, among others. Sea Ray’s innovative Venture 370, with its hidden Mercury 300s, benefitted from Seaway’s concept definition, naval architecture, interior and exterior design, engineering prototyping and testing.

Group Beneteau approached Seaway to design a hybrid drive system for boats it was contemplating building. Volkswagen, motivated by hybrid possibilities for its cars, joined the project. When Beneteau scrapped its plan, Seaway went on to finalize the development of that diesel-electric drive system. Volkswagen tagged along, and Seaway began building under the Greenline brand, and since 2010 more than 300 of the 33-footers have splashed down, mostly for use in Europe. A larger 40-footer has also entered the marketplace, and a new 46-footer was introduced at the 2014 Dusseldorf boat show.

Sea_05-2014_Cumberland_031Because weight sops up power and tends to reduce speed, Greenline boats are built as light as possible without sacrificing strength or rigidity. Hulls are vacuum infused, using epoxy-based vinylester resins. Lightweight composites are used in the stringers and liners, which are chemically bonded to the hull and deck. Lightweight plywood is used throughout the interior. Seaway’s extensive engineering and structure experience has been put to good use in the development of this line of hybrids, so as to keep weight to a minimum.

The 33 hull has a pair of fixed fins projecting down from each side of the hull. They act as passive stabilizers to dampen roll and improve tracking. The fins will break off if they strike anything, without affecting the watertight integrity of the hull; they are easily replaced.

Hull Design
According to the builder, Greenline hulls are “low drag,” which implies they are very efficient. They have a sharp entry at the bow with a fairly plumb stem. As the hull runs aft, the bottom flattens until there is almost no V at the transom. The bottom flattening enables the boat to move along briskly with relatively little power required. It also means the vessel, as it moves more quickly through the water, rises and reduces the wetted running surface, cutting down on drag. It also means the hull moves smoothly and efficiently through the water at lower speeds. In fact, at speed/length ratio 1 (full-displacement mode), the 150 hp VW TDI 2.0L (122-cubic-inch) diesel produces a hull speed of about 5.7 knots and the fuel burn is 0.8 gph. That combo translates to 7.2 nmpg and gives a range in excess of 900 n.m.

Owners Will Love
The Greenline designers have opted to bring the outside in, or take theSea_05-2014_Cumberland_041 inside out, depending on how one looks at it. Following a trend emerging out of Europe, the deckhouse’s aft bulkhead — through a combination of a cleverly designed sliding-glass door and a swing-up window — “disappears,” and the cockpit becomes part of the social space. The bulkhead’s “disappearance” takes only seconds and doesn’t require “fiddling” with anything — just slide the door and open a large window. A drop-down section of the counter becomes an outdoor breakfast or lunch nook, so a cruising couple can comfortably snack or dine without ever having to bring the dining table into play. The deckhouse overhead extends far enough aft so rain, or a scorching sun, won’t interrupt breakfast, lunch or happy hour.

The cleverly designed bow accommodations allow a V-berth arrangement to become an island queen. Two berths hug either side of the hull, but both of them can pivot to the centerline of the vessel and form a queen berth. Such a feature was further enhanced by Boston Whaler, who upgraded and set up a remote-control system to do the same thing on one of its new models. Whaler won an Innovation Award at the 2014 Miami International Boat Show for its treatment of the idea.

The Greenline seems to have more window glass than fiberglass in its top sides, which makes for great visibility and a bright, cheery interior even on a dull day.

Signature Feature — Shhh
We stepped aboard the vessel via the power-operated tailgate-style transom, which was lowered to exactly dock height, making getting aboard quick, safe and easy. As we moved away from the dock using only electric power, it was a bit eerie to watch the skipper advance the throttle and feel the boat move without hearing any mechanical sound. We made our way silently out of the marina and noticed, as we ghosted along at about 4 knots, the vessel responded quickly to even the slightest rudder input, which made handling very easy, even in tight quarters.

We continued out of the marina and made our way through Vancouver’s Granville Island no-wake zone under electric power. The helm readout continuously gave us information on electrical draw and the mileage available under electric power only.

At the end of the no-wake zone, the skipper turned off the key to the electrical drive system, turned on another key and started the VW 150 hp TDI diesel. It fired up instantly. The switch from electric to diesel took less than 10 seconds. With the diesel operating at 1000 rpm, we made 4.1 knots, about the same speed we had been traveling under electric power. Diesel consumption, at that speed, was 0.4 gph, which translates to 11.1 nmpg. Noise level, measured on a table right above the engine space, was about 67 decibels.

As we ran through our various speed tests, the noise level never went higher than 75 decibels. Top speed was 13.5 knots at 3800 rpm, and fuel burn was about 7.5 gph, which is about 1.7 nmpg. At 9 knots, fuel burn was about 3.1 gph, yielding just a hair under 3 nmpg.

The vessel responded smartly and precisely to all helm input at all speeds. At wide-open throttle, we spun the helm hard over from lock to lock, and the vessel carved the turns quickly without shudder, skip or skid. Cornering was almost dead flat.

Another maneuver this vessel handles very well is going directly astern. Most single-screw boats have a real problem backing up in a straight line, because the stern always wants to claw either to port or starboard, depending on the rotation of the prop. Not so with this vessel, and that is likely because of a large, responsive rudder and the twin passive fin stabilizers. When we returned to the dock, to which we were going to tie stern-to, the skipper backed straight in, not requiring any help from either the bow or stern thruster.

When the diesel is running, the 7 kw 48v electric-drive motor becomes a 5 kw generator that can charge the 48v Lithium-polymer 240-amp-hour battery to 85 percent of full charge in about two hours. Starting batteries, house batteries and thruster requirements are all 12v.

Best Uses
Greenline’s 33-footer does normal “boat things” very well, and the switch from electric to diesel drive is a non-event — just the way things should be. The vessel’s combination of a small diesel and a well-designed “slippery” hull delivers mileage that is almost unheard of in cruisers of this size. The interior layout is fairly traditional, but the cleverly designed pivoting bunks in the bow cabin allow for a general open space, with two bench seats during the day and a double-berth cabin at night.

For boaters who want to move silently around a harbor or a secluded anchorage, the electric operation works flawlessly. Given its range of 20 n.m., the boat has enough juice in the battery for five hours of poking around at 4 knots, or almost double that if a boater is fishing at a slow troll.

The tailgate-style transom is great for either fishermen or owners who want to use some of the various water toys now making their way on the scene. It also allows extra space for socializing.

The Greenline 33 is a good choice for boaters who might like to consider a hybrid, but who are afraid to take the plunge. The Greenline can be purchased “hybrid ready,” which means the hybrid side of the hybrid can be fitted later. The cost of that fitting out will be about $45,000.

Overall, the vessel will make a good coastal cruiser either as a hybrid or with diesel power alone.


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