On April 8, 2023, following The Ocean Bulletin provided 24 hours in advance by Amphitrite, the Ro-Ro vessel Ciudad de Cadiz, chartered by the Louis Dreyfus Armateurs group, deviated a few dozen nautical miles north of the direct route between Sardinia and the Strait of Gibraltar to avoid counter-currents and benefit from positive currents (Figure 1).
Figure 1 Optimized route followed by the Ro-Ro Ciudad de Cadiz in relation to its direct route (blue dotted line). The ocean bulletin forecasts a zone of strong acceleration (in green) with zones of slight slowing (in yellow) along this optimized route.
This small course deviation enabled the Ciudad de Cadiz to increase its average speed from 16.5 to 17 knots for 36 hours, reaching a peak speed of 18.2 knots without increasing engine power. This acceleration, confirmed by the ship’s AIS (Figure 2), was due to an intense anticyclonic eddy to the southwest of Sardinia. Unlike operational numerical models, HIRES-CURRENTS data perfectly position this eddy structure. The technology developed by Amphitrite uses artificial intelligence to fuse multiple satellite data, in particular sea surface temperature (SST). This enables the anticyclonic eddy to be positioned with great precision (Figure 2 left), and the intensity of surface currents to be correctly predicted.
Figure 2 Speed accelerations of the Ciudad de Cadiz (SOG-STW) measured by AIS (top) compared with HIRES-CURRENTS surface currents (left) and predictions from an operational numerical model (right). The ship’s position at maximum acceleration (light blue) and its trajectory are superimposed on the day’s sea surface temperature (SST) observation (bottom).
This short-term optimal routing, based on ocean currents, enabled the Ciudad de Cadiz to save 70 minutes on its route, and ultimately reduce the ship’s consumption by 5% over 36 hours, while maintaining its arrival time at the destination port. A joint press release with the shipping company has been released on the 28/06/2023 (link to the announcement in French).
Further operational tests, carried out in April and May 2023, confirmed the accuracy of the HIRES-CURRENTS data provided by Amphitrite. The potential fuel savings for the Tangier-Tunis-Naples-Tangier rotation have been estimated at between 40T and 100T of fuel for around twenty rotations per year, depending on the optimization mode chosen.
