As an adolescent in the ’80s, I was naturally drawn to the coolest new tech toys I could get my hands on.
The first Apple Mouse? Clicked it.
Laser tag? Zapped it.
The Speak & Spell? My must-have item for family road trips. (Sorry, Mom and Dad—but really, you should have sprung for the attachable headset.)
Fast-forward about 30 years, and all that techy paraphernalia still catches my eye at a boat show, rendering me useless to third-party conversation until I’ve figured out how it all works. That’s why, when I took a Greenline 48 Coupe for a spin on the Intracoastal Waterway with Luca Meffle, Greenline’s head of sales and marketing, I geeked the [bleep] out.
For a trawler guy who until now has largely subsisted in a world of traditional diesels, the implications of a hybrid-electric system came with a bit of culture shock. At first, I didn’t know if this boat was for me, but as Meffle and I peeled away layer after layer of the 48 Coupe, I came to appreciate how the model has a lot to offer any mariner, especially one with a passion for cool tech.
The first thing to notice is the standard solar roof, composed of photovoltaic solar panels delivering 2.4 kW worth of 120-volt AC power at all times, courtesy of a 600 Ah AGM service battery and a 5 kW inverter. The power output is roughly equal to a small generator running all the time, and it allows full use of the 48 Coupe’s appliances—standard fridge and freezer, induction stove, microwave and more—just like at home. The photovoltaic panels also provide additional energy for the boat’s H-Drive or E-Drive system. If you opt for the H-Drive system, the 600 Ah AGM battery and the 5 kW inverter gets replaced by a minimum 40 kWh (and up to 80 kWh) lithium LiPo batteries and a 10 kW inverter, enough power to run a tropical air-conditioning package off the LiPo batteries alone, with no generator necessary.
The 48 Coupe comes with multiple charging and driving modes. In Shore Power Charging Mode, the boat is plugged into shore power at the dock. The battery pack is under charge, and the inverter provides AC power to run home appliances.
In Diesel Drive Charging Mode, the diesel engine propels the boat and drives the electric motor, which acts as a generator to recharge the battery pack. A full charge takes two to four hours on diesel mode, depending on the battery package.
At-Anchor Charging Mode employs the solar panels. The array charges the batteries, which provide AC power to run the appliances via an inverter. If the level of battery charge drops below a set value, then the diesel engine can be switched on to drive the electric motor/generator and charge the battery pack. The propeller remains disengaged, as the gearbox is neutral.
In Electric Drive Mode, the boat’s propulsion is provided by the electric motor using the power from the up to 80 kWh lithium-polymer battery. This zero-emission mode is used when moving in and out of the marina, anchorage or no-wake zones without noise or exhaust. Running on electric power, the 48 Coupe cruises at 6 knots with a range of up to 40 miles.
H-Drive (H for hybrid) employs twin 14 kW Mahle electric engines with integrated 10 kW generators in combination with twin 220-hp Volvo Penta D3 diesel engines. (Or, forgo the hybrid package completely and opt for twin 480-hp Cummins engines.) Running on diesel with shaft drive, cruising speed is around 15 knots with Volvo Penta D3s. Top speed with the traditional Cummins engines is 30 knots.
Given all the variation in modes and speeds, I expected consistency in performance to be an imperfection, but the 48 Coupe’s hull laid my concern to rest. It’s an evolution of Greenline’s “super-displacement” hull design, which incorporates properties of a modern sailing boat’s hull. It’s designed to slice through the water with minimal drag, and to exceed theoretical hull speed, which is determined by the length of the waterline. The hull exhibits added stability via a low center of gravity, and covers the range from zero to more than double displacement speed.
The whole package yields fuel consumption as little as one-quarter that of a semi-displacement, twin-engine planing boat, according to Meffle.
Our ride took place on a spectacular, sunny South Florida day, and at one point, while doing about 5 knots in E-drive mode, Meffle pointed out that our energy intake was greater than our output. To put that in context, think about the Great Loop, with all of its bridge openings to wait for and long stretches of waterway to creep along at idle speed. We were doing 5 knots, in silence, putting no diesel hours on the engines, and we could keep going for as long as the sun held out.
That begged the question: Could someone actually do the entire Great Loop on electric mode alone?
Technically, yes, Meffle says, but from a real-life cruising perspective, it’s obviously not practical (though it might make one hell of a story).
The 48 Coupe’s modern-classic lines resemble those of her sistership 48 Fly, with shared features including a low cockpit and salon sole, a side boarding door, large salon windows, protected side decks, and Greenline’s bulwark aperture at the bow to accommodate the master stateroom’s 180-degree panoramic windows.
Cruiser DNA is evident in the 48 Coupe’s living and entertaining areas. The boat’s one-level living concept includes a flush deck from the cockpit through the salon, linked by an open galley. The salon has a U-shaped dining area. A side door at the helm area facilitates single-handed maneuvering.
A transom-mounted wet bar is accessible from the hydraulic swim platform, and includes a grill, a sink and a worktop for preparing the catch of the day. The foredeck has sunpad seating with lifting backrests and a convertible Bimini top.
The 48 Coupe accommodates six people in three ensuite staterooms, with the master in the bow and two guest staterooms with twin berths amidships. The master can be ordered with Greenline’s scissor berths or with a queen-size island double, plus a closet and a separate shower compartment in the head. The starboard stateroom’s head doubles as a day head. An optional layout affords just two, but larger heads. A crew berth is accessible from the cockpit.
Beyond the boat’s geography and physics, the real poetry of the 48 Coupe, for me, is its self-sufficiency. The ability to stay out on the water a little (or a lot) longer, with zero dependency on marinas for shore power hookups or water supplies, is a game changer for extended cruising.
As of this writing, another 48 is nearing the finish line of her first Great Loop. I have to wonder how many zero-decibel engine hours she spared her owner along the way.
GREENLINE 48 COUPE SPECIFICATIONS
LOA: 47ft. 2in.
Beam: 15ft. 8in.
Draft: 3ft. 1in.
Displacement: 30,423 lbs. (dry)
Engines: (standard) 2 x 320-hp Yanmar
Engines: (optional) H-Drive 2 x 220-hp Volvo D3 with 2 x 14 kW electric motor; 2 x 370-hp Cummins; 2 x 480-hp Cummins
H-Drive Speed (max.): 15 knots (diesel mode) 6 knots (electric mode)