LAGOON 420 HYBRID BOAT REVIEW

Hybrid powerplants are all the rage among environmentally conscious motorists, but a sailing boat such as the Lagoon 420 Hybrid actually makes a better environmental and economy platform than a car, reckons ALLAN WHITING.

The 2008-model 12.6-metre Lagoon 420 looks the same externally as its predecessor, only the interior has been redesigned. In place of the previous cherry finish is horizontal-grain light oak panelling, contrasting with dark-finish laminated flooring. It looks chic, contemporary and, well, compelling.

Either way, nice wide stairs lead up from each hull into a vast saloon spanning bridging them that features a wraparound settee, island seat, dining table, gallethy with three-burner stove, oven and microwave, fridge, chart table and ample cabinet space.

The saloon's design is practical rather than rakish, with vertical sides and windows that maximise interior space and keep the sun at bay. A sliding glass door opens onto the bridge deck, which has another dining area and a twin-seat bench steering station under a fibreglass post-mounted bimini.

The wide decks have adequate anti-slip finish and are punctuated by flush hatches that light and ventilate the hulls. Certainly, you don't feel like you are squirreled away when hunkering down in this upbeat French cat. Nor do you feel as though you will be tossed overboard when above decks. Ah, level cat sailing.

DIFFERENT STROKES

The Lagoon 420 has no transverse beam connecting the hulls at the bow - she is made with a one-piece hull mould with a one-piece deck fixed atop that - but features a pod extending from the cross-hull moulding.

It's best to visualise the bow as a fork, with a centre prong supporting the forestay and housing the chain locker and electric windlass base. And there are dolphin-spotting nets either side of the central moulding.
 
The profile of the Lagoon 420 is chunky, thanks to its vertical bows and coach house, but this practical shape is surmounted by a tall rig with a powerful 98m2  sailplan. The main is fully battened and drops into a zippered bag, guided by lazy jacks, while the headsail rolls onto a furler. Easy.

The mast is stepped on the saloon roof, with a polished compression post inside the boat. Run aft, the wide-based shrouds make a backstay redundant and the single-spreader rig is well triangulated.

Sail handling has been given considerable thought and all lines lead to the starboard steering station, where a bank of three winches ? one electric - handles white-sail duties. A fourth winch on the port side accepts the optional gennaker sheet. The mainsheet traveller is mounted on the bimini roof, attached to its heavy support posts.

GOING GREEN

The Lagoon 420 Hybrid's propulsion system consists of a 72V 10kW electric motor and six 12V deep-cycle batteries in each hull (the standard model has diesel saildrives). Because each electric motor is light compared with a diesel engine and leg, the batteries are installed aft in each hull to preserve hull trim.

An Onan 11kVa generator used to be installed in a bridgedeck locker as part of the Hybrid package, however, the test boat was fitted with a larger 17.5kVA gennie that, although optional at the time, is now the standard offering.

Dollar-wise, the Lagoon 420 Hybrid may seem a tall ask at $803,000 for the three-cabin owner version compared with $752,000 (sans generator) for the same boat with diesel engines. But much of that price hike is the cost of the optional generator on the diesel version. And what cost can you put on going green?

"THERE"S NO NEED FOR A WARM-UP, NO NOISE AND NO DIESEL FUMES"

In the Hybrid's steering station, the wheel, autopilot panel and twin-throttle levers are the only familiar items in the helmsman's view. In place of the usual instruments is a panel of five red and green gauges that monitor electric motor operation and the charging systems. There are also four LEDs that indicate the electrical system's operating mode, as well as buttons that activate or turn off the electric motors.

Moving out of a berth is done in the usual way: by playing the throttle levers. Only the operation is silent, except for the faint rumble of the propeller shafts and the stirring of the water. There's no need for a warm-up, no noise and no diesel fumes. Also, there's no clunking between forward and reverse, because the instant torque of the electric motors makes a transmission unnecessary (if only the early birds berthed nearby had Lagoon Hybrids!).

Once clear of obstacles, the Lagoon Hybrid powered along happily in still water at a shade under five knots, with the engine 'consumption' gauge registering a draw of 75 amps. A push on the 'turbo' button allowed full electrical power draw of 150 amps and speed went up to nearly seven knots. This mode can be held for up to 10 minutes, after which the system reverts to normal consumption levels, but it's handy if you need a temporary speed increase.

The early Lagoon Hybrids were over-sensitive to battery-voltage drop, which triggered the back-up generator after a short period of motoring. The system we evaluated has been updated, allowing around an hour of current use at the 75-amp setting before the gennie kicks in at 80 per cent of battery capacity.

SETTING SAIL

After draining some battery power and turning off the electric motors, we swung the Lagoon's noses upwind and powered the main up the stick with the foot-controlled electric winch (not to self: save up for one of these). The headie came out of its roller slumber easily and we bore away on a broad reach.

The luxurious Lagoon 420's 13.4-tonne bulk demands a reasonable amount of air movement, so not much happened until the morning breeze puffed above 10kts. Then the water gurgled around the hulls and we were soon surging along at seven knots.

On the point, the speed dropped to around five knots but, for a big cat, an upwind angle around 40 degrees is more than acceptable.

While we were sailing along there was the faintest rumble from the propeller shafts, doing their regenerative charging thing. Once the speed hit around 4.5kts the electric motor 'fuel' gauge needles and battery current pointer swung into the green zone, denoting amps going into the battery bank.

In theory, the longer and faster you sail without using the batteries the more they recharge. The regenerative system is designed to cut out when the batteries are fully topped up or if hull speed exceeds 18kts.

TAKE CHARGE

Of course, there's no such thing as a free lunch and the regenerative charging function saps some sailing speed by causing 'drag' on propeller rotation. Vicsail, the Lagoon distributor, estimates a maximum of one-knot speed reduction while recharging is happening.

With many Lagoon Hybrids now operating around the world ? already three in Australian waters - there's ample evidence of the economies the hybrid system bestows. More important is reduced dependence on diesel tankage and resupply when making long passages.

The global experience with Lagoon 420 Hybrids is building and the worst case scenario seems to be around seven hours of regenerative sailing to make up for an hour's motoring, with about half the overall fuel consumption of a conventional diesel-auxiliary catamaran.

These findings back up Lagoon's decision to fit only one 300lt fuel tank as standard in the 420 Hybrid, in comparison with twin 300s in the diesel models.

LIVING WITH THE HYBRID

The Hybrid system promises easier long-term cruising and less maintenance than with a conventional auxiliary diesel/generator system. The charging options are shorepower, the onboard generator and regenerative sailing.
Owners report the much greater battery capacity of the Hybrid gives them more time away from liquid or electrical 'refuels'.

Although the regenerative system works well when the craft is sailing, some owners have found that additional charging, such as from wind and solar, has proved useful in keeping battery levels up when the boat is moored for long periods.

Lagoon claims a life of 20,000 hours for the electric motor shaft bearings, which means that most original owners will never wear them out. However, long-distance cruisers will need to replace them every few years, because every sailing hour is a bearing-wear hour.

A great benefit of the Hybrid system is that there's only one diesel engine to maintain, instead of three in the case of a cat with a generator.

The automatic charger operation of the Hybrid should guarantee long battery life, but the 12 batteries obviously have a finite existence. However, some of the fuel savings can be put aside for that eventuality.

Given the likely cruising vocation of the Lagoon 420 Hybrid, the specification seems ideal, promising the lowest cost, most environmentally kind system on the market today. Full marks for a cat that paves the way of the future.

HYBRID ON THE HIGH SEAS

Hybrid propulsion systems fall into two camps: parallel hybrids and series hybrids, the latter being fitted to the Lagoon 420.

Parallel hybrids have an internal combustion (IC) engine, driving through an electric motor-generator unit, to a transmission or leg. A parallel hybrid powerplant can operate with electric power alone, with IC power alone, or a combination of both. The new Steyr marine hybrid package is one example of a parallel hybrid.

Series hybrids also need an internal combustion engine, but instead of being coupled to a conventional driveline their engine drives a remotely mounted electric generator, which powers electric propulsion motors, via a large battery bank. The Lagoon 420 Hybrid uses just such a system.

In both hybrid variants there is a battery pack that is charged by the internal combustion engine and by regenerative action when the vessel is sailing.

Generally, a parallel hybrid has less battery power for exclusively electric propulsion than does a series hybrid. And where a large battery pack is a heavy nuisance in automotive applications it's often a ballast-bonus in a boat like the Lagoon 420 Hybrid.

HIGHS

Quality fit and finish
Generous accommodation
Vast deck and 'sprawl' space
Self-contained cabins
Shaded saloon
Excellent light entry and ventilation
Quiet progress under power
Cruising and motor-sailing economy and range
Power winch for easy sail handling

LOWS

No handrail around well-deck lounge
'Hunting' nature of catamaran steering
Steep access to bimini top for mainsail stowage

SPECIFICATIONS
Lagoon 420 Hybrid

PRICE AS TESTED

$862,650 including options. Options fitted: gennaker with pole and 'snuffer'; tender davits and winch; holding tank and quiet-flush toilets; Raymarine 2007A nav, VHF and E80 chartplotter and autopilot; anchor kit.

Priced from $752,000 for 40hp diesel sail drive (non-hybrid) model

General

Material: FRP hulls and decks - balsa core composite above the waterline and solid FRP below
Type: Catamaran
Length overall: 12.61m
Beam: 7.50m
Draft: 1.26m
Weight: 13,400kg

Capacities

Berths: 3 (optional 4)
Fuel: 300L
Water: 350L

Sails

Mainsail: 62m2 fully-battened
Headsail: 35m2 furling genoa

Engines

Make/model: 2 x 72V plus 17.5kVA generator and two 6 x 12V battery banks (210AH)
Type: Electric DC- straight shaft
Rated hp: 10kW
Props: Fixed - regenerative charging type

Supplied by Vicsail, d'Albora Marinas, New Beach Road, Rushcutters Bay, NSW, 2011.

From Trade-a-Boat Issue 382, Nov-Dec 2008. Photos: Allan Whiting and Beneteau