How to be more fuel efficient

Jake Kavanagh looks at how the shipping sector saves fuel and how this is filtering down into the leisure motorboat market

- Jake Kavanagh

The shipping sector is on a mission to reduce emissions and cut running costs, and some of its ideas will translate directly to pleasure boats.

There is a lot of pressure on the commercial shipping sector to improve fuel efficiency ahead of a 2030 deadline, with full decarbonisation by 2050. Although this sector, comprising around 56,500 vessels of over 1,000 tons, carries 90% of the world's goods for just 3% of global emissions, it is still a major international target for sustainability.

As fuel makes up a major ongoing cost, the industry has been seeking new ways to reduce the amount it uses. A champion in this field is the Norwegian assurance and risk assessor DNV, which has just produced a 91-page document entitled 'Energy-efficiency measures and technologies.' (dnv.com/maritime/publications/energy-efficiency-reportdownload). As with anything to do with shipping, several ideas can filter down to leisure craft of all sizes. DNV estimates that if just some of these ideas are implemented, the average ship can reduce its emissions by 16% by 2030. That is equivalent to the total emissions of the 2,500 largest ships in the world today.

We've looked at some of the more practical ideas helping ships use less fuel, and which might be adaptable to the leisure sector. These are probably the most practical and transferable.

Wake-adapted stern gear

An area showing proven results for efficiency gains and noise reduction is in 'wake adapted' or 'velocity aligned' stern gear. The term is used to describe any part of the underwater drive train that is specially shaped to both harness and mitigate the turbulence of propulsion. A clear indication that a vessel has this technology is the shape of the rudder, which appears to be twisted. In fact, it has been deliberately warped to better align with the propeller wash.