A joint demonstration at Cannes keeps a 250hp petrol outboard in place and adds two retractable electric motors for low speed manoeuvring and docking.
Mercury Marine and French electric propulsion company BlueNav have jointly demonstrated a hybrid propulsion installation ahead of this week’s Cannes Yachting Festival.
This is not a hybrid outboard in the sense of one drivetrain blending two energy sources. It is a boat fitted with two separate propulsion systems: a 250hp Mercury SeaPro handling normal running, and two retractable 8kW BlueNav electric outboards handling low speed manoeuvring. Neither drives the other’s propeller.
The demonstration vessel is a Highfield Patrol 700, a 6.99m rigid inflatable rated for a single outboard up to 250hp. The SeaPro remains primary propulsion for speed and distance. The two BlueNav units, mounted either side of it, produce a combined 16kW and are intended for the phases of a passage where low speed control matters more than power: entering a marina, holding position, or manoeuvring in a confined berth.
BlueNav’s Smart Navigation software adds Virtual Anchor position holding, Smart Mooring and a 360 degree docking mode. The company estimates manoeuvring below five knots accounts for close to 30 per cent of time spent underway, the window this system targets.
A retrofit proposition
BlueNav markets the BlueSpin units for both new builds and retrofits, installed without removing an existing outboard. That distinction matters to an owner: adopting electric capability does not require giving up a serviceable petrol engine, nor its range.
The company is not confining this architecture to Mercury. A second installation, a Honda powered Tiger Marine 750 Open Fishing carrying the same twin 8kW configuration, developed with Tiger Marine France and Boats Distribution, is due at Grand Pavois in La Rochelle later this month. BlueNav also introduced an 11kW motor at boot Dusseldorf in January, its first built around an in house turbine. Together, these releases suggest a company positioning its hardware and software as compatible with established outboard brands rather than competing against them.
Note
Battery capacity, installed weight, electric only range and any measured fuel saving are yet to be published. BlueNav has noted some Mercury V6 and V8 engines carry alternators rated up to 115A, relevant to recharging the electric system, though that figure describes the engine range generally rather than this installation. The BlueNav system operates at 48 volts, and without published figures for battery capacity, charging rate and conversion losses, it is not yet possible to establish how much combustion running time would offset an hour of electric use.
