Update São Sebastião
Our most dedicated followers may have noticed that we have updated our voluntary routing recommendations for São Sebastião in Brazil. This is part of an ongoing process to align our existing routing recommendations with our application. Within our application, we have chosen to work with Areas to Be Avoided (ATBAs) and Speed Reduction Zones (SRZs). We have moved away from recommended waypoints, a method we used in our early days back in 2021.
But why?
The reason is simple. Working with ATBAs and SRZs allow users of our recommendations to choose their own actual routes within the parameters set for whale protection, while minimising interference with the mariner's decision-making. A set of recommended waypoints does not offer much wiggle room and pushes users towards an all-or-nothing solution. ATBAs and SRZs allow for the necessary shades of grey, enabling mariners to work within the parameters of whale protection while ensuring the safest possible route for their particular vessel.
Additionally, working with ATBAs and SRZs makes it easier to monitor both the impact of and compliance with our routing recommendations. Either a ship enters an ATBA or it does not, and either a ship complies with the speed reduction recommendation within an SRZ or it does not. Monitoring compliance with a set of recommended waypoints was much more complicated.
To be an ATBA or not to be an ATBA, that is the question...
The term "ATBA" is nothing new in the maritime world. ATBA is defined in the General Provisions on Ships' Routeing, established pursuant to Regulation V/10 of the SOLAS Convention. An Area to Be Avoided (ATBA) is defined as "a routing measure comprising an area within defined limits in which either navigation is particularly hazardous or it is exceptionally important to avoid casualties and which should be avoided by all ships, or certain classes of ships".
Did we borrow this terminology for our routing recommendations? Kind of... but with good intentions. We made the strategic decision to use the term because it is widely recognised among seafarers and immediately conveys what is expected of them. We could have created a new acronym, but it would not have enjoyed the same level of recognition as the well-established term "ATBA".
I live in a country where creating acronyms is a national sport. Just take a look at the ridiculous abundance of acronyms in Dutch legislation, and you might start to think that there must be a civil servant in charge of this madness...
But I stayed strong and resisted the temptation. ATBA it is at Whale Guardians!
If my integration into the Netherlands had been entirely successful, I would have gone for the unbeatable "AWPIWPATTBA", short for Area With Potential Increased Whale Population And Therefore To Be Avoided...
How do we monitor speed in an SRZ?
In addition to ATBAs, we have been introducing Speed Reduction Zones to encourage transiting ships to reduce their speed. Lower speeds mean better protection for whales, as they give the animals a little more time to evade passing ships. Additionally, lower speeds allow mariners to take evasive action more effectively when whales are spotted nearby. Where whales and ships cannot be separated, speed reduction is widely recognised as the next-best option for protecting whales.
So, we set a speed limit and then simply give a green or red light when measuring the speed of a transiting vessel? Unfortunately, it is not that simple.
Our system obtains speed data from the ship's AIS signal, which typically provides the vessel's speed over ground. This can differ significantly from the speed at which the vessel is moving through the water.
Speed through the water is the speed at which a ship moves relative to the surrounding water as a result of its propulsion (usually an engine, but sails can also provide propulsion). To determine its speed over ground, the vessel's speed through the water must be considered alongside the effects of currents and wind. If a vessel travels at 7 knots through the water and encounters a following current of 2 knots, it will have a speed over ground of 9 knots. Conversely, if it encounters an opposing current of 2 knots, its speed over ground will be 5 knots.
AIS gives us speed over ground, but when we talk about speed reduction for whale protection, we are actually referring to speed through the water. This is the speed a ship can control through its propulsion: the crew can increase or decrease the power applied to the vessel's propulsion system.
We are developing our impact-monitoring function to take this difference in speeds into account as far as possible. However, without real-life data from the ship's sensors, any assessment will always remain an educated estimate.
The added benefits of a SRZ
Reducing speed is better for whales, but it also has a very welcome by-product for shipowners and local communities alike.
The graph below illustrates the relationship between engine load and fuel consumption for a typical ship's engine. This relationship is non-linear, with fuel consumption increasing significantly at higher engine loads. Particularly at these higher loads, a small reduction in engine power can result in substantial fuel savings. For example, reducing engine load from 80% to 70% will generally save more fuel than reducing it from 50% to 40%. Put another way, increasing engine load from 80% to 90% generally consumes more additional fuel than increasing it from 40% to 50%.
An important detail to add is that the below graph show Fuel Oil Consumption (FOC) over time and it does not take into account Specific Fuel Oil Consumption (SFOC) which is a measure for the efficiency of an engine (how much fuel is needed to produce 1kW of power?). The graph is made with AI and is based on generic data, not on a specific ship or engine.
Taking this into consideration, our whale protection recommendations can actually save shipowners money rather than cost them anything extra. Given that passages through our Speed Reduction Zones (SRZs) are generally only 20 to 40 nautical miles long, the additional sailing time is limited, while the fuel savings can more than compensate for it.
Let's take a 40-nautical-mile passage as an example, with a ship capable of maintaining a maximum speed of 12 knots. If our SRZ recommends reducing speed to 10 knots, the additional sailing time will be 40 minutes. Considering that voyages typically last several days, this represents a relatively small increase in passage time. Now let's look at the same scenario from a fuel-cost perspective. Based on a daily fuel consumption of 35 metric tonnes at 12 knots and 20 metric tonnes at 10 knots, the vessel would save approximately 1.5 metric tonnes of fuel over this 40-nautical-mile passage. Of course, actual savings will vary considerably depending on the vessel's type, size, engine and operating conditions.
Nevertheless, this example illustrates the potential financial benefits of complying with our recommendations.
With VLSFO priced at around USD 900 per metric tonne, saving 1.5 metric tonnes translates into approximately USD 1,350 in fuel costs. Not a bad return for an additional 40 minutes at sea and potentially saving whales along the way!
So, what about the benefits for local communities? Well, they have everything to do with the fuel savings mentioned above. When ships reduce speed as they approach or leave a port, they can also reduce harmful emissions in the surrounding area. Air pollution from ships contributes to emissions that are harmful to both human health and the environment. In addition to greenhouse gases such as carbon dioxide (CO₂), relevant pollutants include sulphur dioxide (SO₂), nitrogen oxides (NOₓ), particulate matter and black carbon. Slow steaming has been widely discussed as a way of reducing fuel consumption and, depending on the engine and operating conditions, cutting emissions as well.
Looking around the world, we can see several local initiatives in which authorities are taking measures to improve air quality. Our SRZs could be an excellent tool for achieving two objectives at once: protecting whales and improving local air quality.
Now that's what I call a welcome by-product!
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