It's not just her seafoam exterior that makes 83.5 metre Feadship yacht Savannah a green machine. This 2015 launch uses the Dutch yard's pioneering Breathe propulsion system - which allows for five different operation modes from diesel and diesel-electric combinations to fully electric.

Power comes from a 30-tonne lithium-ion battery bank capable of holding a million watts of electricity. But even in diesel mode, Savannah is highly efficient, with 30 per cent lower fuel consumption than her contemporaries thanks to her dynamic hull shape and steep entrance angle.

The first yacht fitted with Azipods, this 90 metre Lürssen, originally known as Air, has exceptionally low emissions. Ice's diesel-electric generators supply power to two azimuth thrusters, which have the added benefit of giving a comfortable, vibration-free ride.

Not only can this 39.3 metre Newcastle run on 15 per cent biodiesel, but every aspect of Safira's interior also comes from reclaimed, recycled or remnant materials – all without sacrificing luxury.

This 40 metre Holland Jachtbouw is the first J Class to use diesel-electric propulsion. Rainbow's batteries can be charged while sailing and she will cruise in battery-only mode for up to three hours. There’s a lot of green in that pot of gold!

Beyond her olive-coloured hull the 44.8 metre Cheoy LeeDorothea III has a single engine and thruster/backup power arrangement that results in low fuel consumption.

This 41.2 metre sailing boat from Concorde Yachts leaves nothing in her wake. Mirabella III's driving range uses biodegradable golf balls that turn into fish food, and the grey water treatment is state-of-the-art. She also collects ocean data to help with conservation studies.

This 58 metre Royal Huisman is the world’s first hybrid superyacht with an electro-mechanical propulsion system that runs on rechargeable batteries. Ethereal's systems can run for an extended period on its stored energy, while lighting and appliances are energy-efficient.