Slowing down may not seem to be a good advice for many businesses but many shipping lines are saving hefty amounts in fuel by just reducing their speed a little bit.
Marine engine manufacturer Wärtsilä estimates that fuel consumption can be reduced by 59% by reducing cargo ship speed from 27 knots to 18 knots, at the cost of an additional week's sailing time on Asia-Europe routes.
The speed less than 18 knots is called super slow steaming.
This practice of slow steaming in maritime industry emerged during the financial crisis of 2008-2009. During the crisis international trade and demand for containerized shipping plummeted at the same time as new capacity in pipeline came online. As a response, maritime shipping companies adopted slow steaming and even extra slow steaming services on several of their routes. This response helped these companies to accommodate additional ships with similar demand. As an increase of just one knot would free up enough vessels to grow global capacity by 6.2 percent and one further knot would add another 5.9 percent of global capacity.
Slow steaming does involves adjusting the ship engines.
The additional benefit of high fuel efficiency is reduced emission of green house gases. Ships are most efficient mode of transport as far as green house emission is concerned.
Slow steaming may has its own downside. For example Slow steaming' upsets some customers, who worry about delays in delivery. At the same time the risk of pirates attacking the ship increases as Pirates have never managed to board a vessel travelling at 18 knots or more and container ships and other faster vessels have traditionally crossed the high risk area up to 1,500 miles off Somalia’s coast at up to 24 knots.