Eniram Explains Optimal Coastal Routing

Tero Ilus, Director, Nautical Consulting at Eniram talks about optimal routing in the first of a series of three blogs:

Optimal routing is an essential part of voyage planning. Traditionally, optimal routing has been avoiding areas with high risk of cargo damage. With advanced weather forecasting, the forecast period has become longer. With advanced data communication, it is possible to deliver the updated forecasts onboard, and weather routing has become dynamic and adaptive to the real weather and is no longer merely avoidance of high risk areas.

But weather routing is not the only part of optimal routing. As IMO Regulation 34 states:

The voyage plan shall identify a route which:

1. takes into account any relevant ships’ routing systems
2. ensures sufficient sea room for the safe passage of the ship throughout the voyage
3. anticipates all known navigational hazards and adverse weather conditions; and
4. takes into account the marine environmental protection measures that apply, and avoids, as far as possible, actions and activities which could cause damage to the environment.

In practice, this means optimal route should comply with all regulations, navigate through or around shallows and find the right currents and weather. All in a safe and efficient way! It’s not an easy task for a young second officer (as it is usually left solely as the second officer’s task to make the route planning). When crossing the oceans you can concentrate on weather routing, but if the distance between waypoints, forced by the factors noted above, is so short that going around to another weather area is going to make too much extra distance, weather routing is not an issue.

When sailing with different vessels it has become clear to me that while we have really advanced weather routing systems, the other parts of the voyage are poorly optimized. With the help of Eniram’s massive database, I started to look closer into it. I studied how much of the fuel is used in coastal routing (not applicable for weather routing), in our customers’ fleet. 

Even before conducting the study it was clear to me that on cruise vessels this number was high – and it was over 90 percent. But for the container vessels it was almost 50 percent! When digging deeper, it actually makes sense: the whole traffic in East China Sea and South China Sea is coastal, traffic in South America (both sides) is coastal and if you think about it – even Europe-Asia voyage is almost entirely coastal. Actually, in theory, the legs from the Gulf of Aden to Sri Lanka and further to Malacca Strait are weather routing areas but in practice they are not. Also the beginning and end of the ocean voyage is coastal.

So we are talking about a huge amount of fuel used in coastal routing. But still, if you think about route optimization systems, you will find only weather routing providers. Why is that? Well, the coastal routing optimization is not an easy task – it does not have a mathematical solution. And engineers hate that. You need to have the knowledge of an experienced navigator, database of all rules and regulations in the world, knowledge of high risk areas, understanding of individual vessels squat, sea state and wind behavior, accurate forecast of wind waves and currents, accurate water depth charts and possibility to calculate optimum of all these factors. The human brain (not even a sailor’s brain) can’t do it and a computer program would be so complicated that no one would buy it (if it even works).

Our calculations show an average of about five percent savings potential in coastal routing. So how to save in coastal routing? Why not combine the navigator’s brain and computer algorithms? I will explain all this in the next part of The Whole Picture.

Source: Eniram