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Brief Summary

The Greenline 48 Fly is a diesel and solar-powered cruising vessel. Onboard amenities include a single-level living design for the main deck, a fly bridge with a wet bar and sun lounge and a hybrid system that can power the electrical systems without shore power. This vessel is ideal for a couple or family looking to cruise longer at a leisurely pace in near silence. Or, she can get up on plane for shorter runs.

Key Features

  • Hybrid solar and diesel power generation
  • Sheltered side decks
  • A master suite and two guest cabins with separate head compartments
  • Two solar panels standard
  • Constant 240 V power available


Length Overall 49' 2'' / 14.99 m
Beam 15' 9''
4.80 m
Dry Weight 30,423 lbs.
13,800 kg
Draft 2' 9''
0.84 m
Deadrise/Transom N/A
Max Headroom N/A
Bridge Clearance 18' 1''
5.51 m
Fuel Capacity 396 gal.
1,499 L
Water Capacity 174 gal.
659 L


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Engine Options

Tested Engine Currently no test numbers
Std. Power 2 x 220-hp Volvo Penta D3 EVC E

Captain's Report

Contents of Report

Greenline 48 Fly

The Greenline 48 Fly is the company’s flagship vessel with an upgraded interior, advanced hull design, and long-range capabilities.


Built for extended voyages, the Greenline 48 Fly is a serious consideration for boaters looking to upgrade their lifestyle.
While the boat is spaciously laid out and fitted with a long list of amenities to make onboard living comfortable, the hybrid propulsion system offers convenient power generation and independence from shore, as well as offering silent and emission-less navigation.

Major Features

    • 230 Volt AC power available at all times

    • Utility compartment under salon

    • Three different boarding heights: the swim platform, side deck, and bow

    • 360-degree view from the salon

    • Fly bridge with helm, lounge, and wet bar

    • Silent and emission-less propulsion capability

Greenline 48 Fly aerial

The standard array of photovoltaic panels allows the vessel to use electric power for the propulsion and house electronics.


Brothers Jernej and Japec Jakopin have produced more than 300 sailboat and powerboat designs since the creation of their J&J Design Studio in 1983. The brothers founded Greenline Yachts in 2009 to design powerboats that would appeal to those looking to upgrade their lifestyle with a more ecological-friendly yacht.

The hybrid hull of the Greenline 48 Fly is an evolution of their displacement hull design. Inspired by low-drag sailboat hulls, the 48 Fly is streamlined to cruise efficiently at both displacement and higher speeds, while stabilizers affixed to the hull surface contribute to the vessel’s stability.

The construction process involves vacuum infusion to create a hull that is strong, light, and stiff.

Greenline 48 Fly hull

The hybrid hull design allows for efficient movement through the water and increased stability, according to the builder.

Features Inspection

Greenline 48 Fly running

The 48 Fly has living accommodations for six passengers, plus the option for a crew berth.

Performance with Diesel Propulsion

The 48 Fly is equipped with two Volvo Penta D3-220 horsepower engines, which can be upgraded to Volvo D4s with 300 horsepower, or Cummins QSB 6.7s with either 380 or 480 horsepower.

As a vessel built for medium-range voyages, it can carry 396 gallons (1,500 L) of fuel. The builders report that the engines have a range of approximately 657 nautical miles at 7.3 knots, with a 10 percent reserve of fuel.

BoatTEST has not performed speed trials of the boat, but has inspected it.

Greenline 48 Fly running

The Greenline 48 Fly is designed to be a cruiser, and the speed will determine how far the boat can go.

Speed Numbers. The folks at Greenline tell us that they have tested the boat powered by twin Volvo D3 220-hp diesels. At WOT, which was 4040 rpm, the 48 Fly had a top speed of 17.4 knots, or 20.02 mph.

Best cruise came at 3600 rpm where she reportedly traveled at 14.9 knots, 17.14 mph, and burned 19.02 gph (72 lph) for a range of 279 nautical miles.

At Slow Cruise. Greenline tells us that at 1200 rpm, the vessel will go 5.1 knots (5.8 mph). The boat burns .89 gph (3.4 l) and has a range of 1,668 nautical miles. That is an interesting statistic for anyone willing to go that slow.

Greenline 48 Fly e motor

The middle arrow is pointing to the “E-Motor” which is both an electric motor and a generator. The arrow to the right points to the V-drive transmission and the arrow at the bottom is pointing to the shaft that can barely be seen.

Hybrid Features

The hybrid propulsion system comprises of the two diesel engines and a pair of 14-kilowatt Mahle electric motors, with an integrated 10-kilowatt generator. The Mahle unit is both a motor and a generator (thus is called an “E-Motor”). The shaft from the engine passed through the middle of the motor and on to the V-Drive.

Solar energy is collected by two photovoltaic panels, which are installed on the roof of the main cabin. Four more panels can be installed as part of the fly bridge hardtop package. Solar power is stored in three lithium-polymer battery packs, located in the engine room, which can each carry up to 11.5-kilowatt hours and have an estimated 10 years of life expectancy.

Greenline 48 Fly solar panels

These solar panels can power the boat’s refrigerator and other vital accessories when the boat is on anchor and there is sunlight.

Essentially, there are two sets of batteries, the normal house, thruster, and house batteries in addition to the three lithium-polymer batteries to power the electric motor. These batteries can be charged by shore power, the diesel engines’ alternators, the E-Motor and by the solar panels. When electrical power is wanted, the lithium-polymer batteries provide the power for the electric E-Motors.

Run Silent for Day Boating. The vessel is nearly silent when the electric motors are powering the propulsion. Ideal for slow-speed maneuvers such as docking or station keeping, the builder reports that the vessel can travel at 4 to 5 knots with a fully charged battery. We’re told that the motors can keep up that speed as long as they have a charge. Typically, we’re told, that the motors can be powered for about two hours at those speeds.

New Way of Boating

The trick is to learn how to use the hybrid system. Basically, it is to play to the strength of the system, which is providing low-speed propulsion and silent running. For example, typical diesel-powered boats spend 30 percent of their time at idle – leaving a marina, going through no wake zones, through anchorages, waiting for bridges to open, trolling, and otherwise gliding around.

These are the times to use the E-Motor’s propulsion. By doing so, it saves diesel engine hours, and perhaps even maintenance as diesel is likely to be run at 80% load. While they sip fuel at idle, over the course of a season, the fuel savings can add up to several hundred dollars.

Perfect for the ICW. Perhaps the best place it uses the hybrid system is cruising up and down the ICW. Here, by using the E-Motor when going through the no wake, then switching to diesel power in the open stretches, the vessel won’t lose time, and in the process it will be charging up the batteries for the next no wake zone and the electric motor.

Even when coastal cruising, why not slow down and smell – and hear – the roses for an hour or so, then return to diesel power, make up time and charge the batteries at the same time? By keeping an eye on the charge in the Lithium Polymer batteries, it won take long before an operator knows when to use the electrical power and when not to.

Greenline 48 Fly buttons

Switching from diesel to electric is as easy as pressing a button located on either helm.

Solar Power

The standard solar panel set up provides enough energy to power the electrical systems on board, including the full-size refrigerator. However, to run the air conditioning solely with solar power, it is necessary to have the hardtop package. The system cannot be indefinitely recharged just by solar power when under constant use. When on a mooring, the solar panels can power certain systems indefinitely – so long as there is sunlight.

Mooring Work. One of the best applications for solar power is when the boat is put on a mooring for the summer. Typically, the boat sits there during the week unattended and then is used on the weekend. The 48’s solar panels will keep the refrigerator and freezer working, keep the icemaker cold and ready, the bilge pumps handling the normal drip, and even run other low-draw appliances.

Solar Saves. Solar power is important for people who want to keep perishables in their freezer and refrigerator during the week while the boat is on a mooring and sitting idle. The cost difference between a mooring and a slip with shore power can range from $5,000 to $10,000 or more, for the summer, depending on the location.

No Generator Needed. With Greenline’s hybrid systems, there is no need for an auxiliary generator. Typically, a 20 kW generator will cost anywhere from $25,000 to $40,000, depending on the make and installer. Each of the Greenline 48 Fly’s two E-Motors put out 10 kW for a total of 20 kW. That power charges all of the batteries and keeps the vessel purring with air conditioners on, the washer and dryer working, in addition to the electronics.

In crowded anchorages, there is nothing worse than a big cruiser running its generator all night, with its swish of coolant water being pumped out constantly. The Greenline 48 Fly is always a welcome neighbor in an anchorage.

Greenline 48 Fly refrigerator

The Greenline 48 Fly comes standard with a small household size refrigerator and freezer, both of which can be kept serviceable with solar power.

Modes of Operation

During Shore Power Mode, when the vessel is plugged into the 230V AC power supply at a dock, the battery pack will be charged and the inverter provides power to run the electrical appliances.

Anchor Charging Mode is a setting to use the solar array to charge the batteries, which provides power to appliances. If the battery level drops below a set value, the diesel engine will switch on to provide power to the generator and charge the battery pack.

Diesel Drive Mode sets the vessel to use diesel to propel the boat, power the E-Motor generator and recharge the battery pack.

Electric Drive Mode uses the electric motor, powered by the lithium batteries, to run at low speeds so long as there is a charge.

Greenline 48 Fly ac layout

To operate the A/C system without using the diesel engines requires four more solar panels, which are included with the optional hardtop. Greenline calculates that the system requires 12,000 BTUs for the master stateroom, 18,000 for both guest cabins, and between 16,000 BTUs and 12,000 for the salon.

Swim Platform

The full beam swim platform is 4’ by 7’ (1.22 m by 2.13 m), with enough space to stow a small tender. Our test boat had the optional hydraulic lowering system, which is activated by a hull side switch. When the platform is lowered, it can be reached from the deck by a fixed ladder built in line with the walkway leading to the aft deck. A boarding gate separates the area when not in use.

Greenline 48 Fly swim platform

Shown is the non-hydraulic version of the swim platform with the removable swim ladder in place. We measured the walkway from the platform to the aft deck to be 21” (0.5 m) wide.

Greenline 48 Fly platform

The platform has pop-up chocks to stow a small tender. These can be adjusted to be nearly level with the rest of the deck when not in use.

Aft Deck

The aft deck features a teak table with a long bench seat that has room for four. An electrically-actuated shade provides coverage over the lounge and swim platform. The shade can be controlled by a button set into the hull and by a remote.

Remove the cushions on the lounge to access the hatch to a utility room. This space houses Victron inverters, hydraulics for the rudder and swim platform. The space can serve as deep storage for other large items, such as a removable swim ladder, or it can be fitted out as optional crew quarters with a berth and enclosed head.

Back on deck, passengers can easily access either of the port and starboard side decks to move forward to the foredeck, or they can ascend the stairs leading up to the fly bridge.

Greenline 48 Fly door closed

Shown is the bi-fold door closed.

Engine Room

Lift the hatch set into the floor of the aft deck and descend the ladder leading down to get into the engine room below.

Inside are the diesel engines, electric motors, lithium-polymer batteries, water and fuel tanks as well as the battery banks for engine cranking, thrusters, house lights, and navigation systems. The diesel engines turn V-drives, which are spinning fixed five-blade propellers, 500 mm in diameter, with twin rudders.

Greenline 48 Fly engine room

The engine room has plenty of headroom. Within view are the standard Volvo diesel engines, transmission mechanics, electric motors and batteries.

Greenline 48 Fly batteries

Shown is a close-up of two of the three lithium-polymer batteries. They have five to six-times the charge of conventional batteries and are seven-times lighter, according to Greenline.


Open the bi-fold door to access the C-shaped galley, which shares an open layout with the salon and helm. The galley is equipped with a sink, wastebasket and electric grill set into the countertop. There’s storage in the cabinets below for galley items as well as a microwave in the starboard cabinets, and a dishwasher set into the center. Opposite of the galley is a full size refrigerator.

The builders designed this area to integrate the indoor and outdoor living spaces. A latch on the aft starboard side window can be released, which enables it to swing down to allow for a secondary countertop to be unfolded and positioned to create a serving bar for the aft deck.

Greenline 48 Fly galley

The galley space is small, but there is a large amount of counter space.

Greenline 48 Fly door

Shown is the bi-fold door open with the countertop accessible from the lounge.

Greenline 48 Fly dishwasher

The dishwasher is easily accessed by opening up the central cabinet.


The salon is integrated in the same open space as the galley, with the seating area positioned forward of the galley. To port is a walnut table with C-shaped seating. We liked that a panel lifts out of the center of the table and flips over to create built-in cup holders. Opposite is a loveseat with an electronically actuated 40’’ (1.02 m), electronically-actuated TV just behind. The TV can be managed via a remote control or with a physical switch.

Greenline 48 Fly salon

We liked the 360-degree view from the salon.

A utility room in the floor is accessed via a hatch and houses a washer and dryer. The room also has space for an optional refrigerator, in addition to serving as general deep storage.

Greenline 48 Fly utility

The hatch to the utility room is to the rear of the main seating area. Note the ladder to enter the space.


The helm station, which is set to starboard and is forward of the salon, has a 360-degree field of vision due to the wraparound windows.

A compass set into the dash is centered above two 12’’ (0.3 m) Raymarine displays. To the left is a screen to manage the battery and waste system. To the right of the displays is the autopilot. Below, and to the left of the wheel, are the diesel engine and electric motor monitoring gauges as well as the battery management gauge and the diesel to electric switch.

Beneath are rocker switches for the windshield wipers, lights, pumps, horns and anchor winch. To the right of the wheel are the controls for bow and stern thrusters, trim tabs, the shifters, and searchlight.

Greenline 48 Fly helm

The Raymarine displays show navigation data and link up to the camera feeds on the aft deck, engine room and foredeck.

Greenline 48 Fly standing

The driver can keep one hand on the controls while preparing to step outside to handle lines or step off the boat.

The helm seat is doublewide with a flip-down bolster. There are storage compartments built into the base. There is a sliding window and an access door immediately to starboard that allows for easy movement to the side deck. There is a cleat that’s within easy reach.


The sun pad on the foredeck is wide enough for three. The aft end can be tilted up to create a backrest while a folding soft top can be positioned for shade. We liked that there were built-in cup holders and there is a removable section in the center of the sun pad that can be lifted out to allow more ventilation into the master stateroom. The forward section of the sun pad can be folded out to create a bench and an optional table completes the area.

Greenline 48 Fly bimini

Shown is the Bimini in place and sun pad with the backrest adjusted to an upright position.

Fully forward are hatches that house the ground tackle and windlass, which can be controlled from the helm and by a remote. The bow rail is split, which is convenient for boarding when the vessel is docked nose in.

Greenline 48 Fly hatches

Shown are the hatches, closed. The left hand compartment houses the windlass, while the right hand has space for storage. The two cleats measure at 10’’ (0.25 m).

Flying Bridge

Ascend the stairs via the aft deck to reach the fly bridge. A C-shaped lounge is on the starboard side, forward of a wide sun pad in the aft section. A small galley with a sink, electric grill and refrigerator is opposite of the lounge.

Greenline 48 Fly fly bridge

Our vessel had the optional hardtop, which offers approximately 6’7” (2.01 m) of headroom. The sun pad is fully aft, and the settee has room for six to 10 adults.

Greenline 48 Fly wet bar

The wet bar comes fully outfitted as standard.

Forward of the galley is a second helm station. A 12’’ (0.3 m) digital display is positioned in the center with the autopilot to the right and a remote control to the left. To the right of the wheel are the controls for the bow thrusters, trim tabs, electrical switches, and engine controls. To the left of the wheel are three Volvo Penta screens, an electric read out, another diesel-electric switch, and a VHF radio.

Greenline 48 Fly helm

Shown is a close-up of the helm. Note the fit-and-finish details on the wheel.

Greenline 48 Fly seat

By adjusting the forward section of the lounge, a companion seat for the helm is created.

Greenline 48 Fly lounge seat

Shown is the converted lounge seat.


The 48 Fly was built with single-level living in mind with the aft deck, galley, salon, and sleeping quarters on the same floor. Below decks has a symmetrical set up with two en-suite guest staterooms to port and starboard with the master suite fully forward.

The guest rooms have a mirrored, identical layout. Each has a hanging locker, a dresser, split berths and a large port light. For lighting, there is a skylight overhead and hull side windows. Both staterooms have an en-suite head with a sink, toilet, and shower. The starboard cabin has slightly less headroom due to the helm station positioned overhead.

Greenline 48 Fly guest

Shown is the starboard cabin. The guest rooms have limited options for natural lighting but the neutral interiors help compensate for that.

The master stateroom is available in two options – as a double berth or with two singles in a V-shape, which can be pushed together to create a single bed, if desired. The room has two hanging lockers and shelving for personal items. There are opening port lights to port and starboard, as well as wraparound windows above storage shelves and cabinets. There are two hanging lockers. The head is split with the sink and toilet in a compartment to starboard with a shower opposite.

Greenline 48 Fly twins

Shown is the split berth option. The two beds can easily be pushed together to create a double.

Optional Equipment

For the most part, the Greenline 48 Fly is delivered ready for cruising. However, there are a few options to consider. The vessel has several options for the layout, including the addition of a crew cabin, a loveseat or an extended bench seat on the aft deck. Other considerations are upgrades to the interior decorations, communication systems, and remote controls for the autopilot.


The price starts at $1,219,695.


The Greenline 48 Fly is ideal for long voyages, such as the Intracoastal Waterway, or for exploring remote locations and dropping anchor far from a marina. While the vessel is not completely independent from burning fossil fuels, the idea of cutting off the engines and spending an afternoon, or alternating between battery and diesel and quietly exploring without disturbing guests, neighbors, and the wildlife is very appealing.

The 48 Fly is not for everyone, but for people who feel better about themselves when protecting the environment, and lowering the decibel level, she is a boat to consider. The future is clearly pointing in this direction, and Greenline seems to be the Tesla of the boating world.