Reviewed by Richard Crowder
“Green is Good” in the minds of most boaters today who are becoming ever more conscious of the necessity of protecting and enhancing the waterways we enjoy and the natural environment that supports it. But “green” is too often only supported if there is little or no sacrifice needed on a personal level in order to achieve it.
Enter Mercury Marine’s Hybrid Concept Vessel, a prototype introduced to great fanfare at this year’s Miami International Boat Show. Mercury’s intention was to indicate what is possible with hybrid power in a family-size cruiser and to showcase its so apparent inherent advantages with minimal physical and personal sacrifices.
Mercury Marine started with a 42’ Maxum express cruiser powered by twin 550 hp Cummins QSC diesels coupled to Zeus pod drives. Between each engine and drive is a high efficiency permanent magnet, 100 hp electric motor/generator. Mercury engineers on hand told me that these electric motors were not restricted to Zeus drives but could be coupled to sterndrives or inboards as well.
At the helm, the driver can select between electric-only, diesel-only, or hybrid modes of propulsion. In the electric-only mode, the motor of course requires battery power. A bank of 300-volt lithium ion batteries with 60 kilowatt-hours of storage capacity fit into a watertight compartment in the bilge below the salon floor. Power converters for the house electrical system are fitted below the front of the forward island berth. The batteries are kept charged in two ways. The most obvious is by the same method we are all used to in hybrid automobiles – the electric motors become generators when not being used to power the boat, ie.- when the boat is being powered by its diesels.
The second method of charging the batteries is, aside from some fairly recent experimentation by university engineering faculties, not found on automobiles, and is a natural for boats, ie.- solar power. There are two solar panel locations on board, both unique in their own way. The first are two bi-facial panels built into the hardtop over the cockpit. Bi-facial panels are themselves unusual in that they are designed to capture the sun’s energy from both sides – directly from the sun, and indirectly from reflected sunlight off the water. The second are four folding deployable panels located under the foredeck sunpad which can be opened or closed as required.
I had a chance to ride in and to drive this unique boat at Miami. Aside from the aforementioned selectable “mode” control, there is nothing at the helm out of the ordinary to indicate its uniqueness. Switching between modes is absolutely seemless. The most unusual sensation is selecting electric-only mode while leaving the dock. There is absolutely no noise. No exhaust fumes. Nothing. Simply put it into gear and leave the dock and feel the instant silent torque of the electric motors. Then couple this instant torque with the diesel engines and this 18-ton boat simply leapt up onto plane.
As you can imagine, Mercury Marine engineers have outfitted this prototype with some advanced electronic controls and monitoring systems, but again, at the helm, and to Mercury’s credit, there is nothing at all unusual to learn. Anyone who has driven a boat of this size can jump aboard and instantly take the helm with no instruction whatsoever. A MercMonitor with an “ECO” screen will help you choose the most favourable fuel economy mode.
One huge advantage of this system is the elimination of an auxiliary generator. Imagine now sitting out at your favourite secluded anchorage with all the power you need all night long – but totally in silence and with no vibration and no exhaust fumes to bother you or your neighbours. The immediate sacrifices that come with this system is the loss of some onboard storage and added weight of the batteries (an addition of about 10% of a boat’s normal weight I was told), plus the added cost. Both will come down over time as more of these hybrid systems are (hopefully) adopted by manufacturers. Kudos to Mercury Marine for starting the ball rolling.
|Length:||42' 9"||13.03 m|
|Draft:||3' 8"||112 cm|
|Dry weight:||27392 lbs||12425 kg|
|Fuel Capacity:||480 US gals||1816.8 l|
|Engine / Drive:||Cummins QSC diesels, Zeus pod drives|