Every time a cruise ship leaves the harbour’s pier is a special moment, ever-present for a real MSC Fans, maybe looking at the manoeuvre, maybe taking pictures, maybe just relaxing seeing the sunset over the sea the ship is almost ready to sail, heading for the next destination. However, before this moment can happen, on the ship’s bridge officers and master have to attend the most important part in the ship’s travel: the voyage planning, here is how.
The voyage planning is based on four points: appraisal, planning, execution and monitoring. Let’s watch one by one in detail.
LONG HAUL APPRAISAL
The appraisal for a transatlantic crossing consists to choose the most suitable track for our voyage. The main tracks are the Rhumb Line (orange) and the Great Circle (purple). The difference between them concerns the ease of following during the sailing. The Rhumb Line is the easiest to follow because the ship keeps the course heading for the entire crossing or almost. On the contrary the Great Circle marks the minimum distance between two points and then the sailing will be shorter, like we can see in the picture, but I will need to change my course heading many times during the navigation.
SHORT HAUL APPRAISAL
The appraisal for a short voyage is more complex due to potential obstacles we can meet during the navigation like tides, tidal currents, restricted areas and more.
Take for example MSC Bellissima’s navigation between Naples and Messina, Italy. On board the cruise ship the crew know that the navigation between the island of Capri and Cape Campanella is not allowed for the cruise ships and for that reason they set the course on 205 degrees to leave Gulf of Naples safely. The following day Bellissima reaches the Messina Strait, an highly regulated area. Indeed all the passenger vessels must follow a roundabout-type Traffic Separation Scheme with a north-bound and a south-bound traffic line, supported by VTS (Vessel Traffic Service). With the maritime pilot on board, the ship approach the north-bound line with course on 245 heading to the harbour of the Sicilian city and keeping the speed under 15 knots, the maximum permitted during summer.
When the appraisal is finished and the best track was chosen the officer proceeds to track the course on the nautical chart or in the ECDIS, the electronic version of a nautical chart.
An ECDIS system displays the information from charts and integrates position information from position, heading and speed through water reference systems and optionally other navigational sensors. In recent years concerns from the industry have been raised as to the system’s security especially with regards to cyber attacks and GPS spoofing attacks.
With the finish of planning the ship is ready to departure. After the sailaway the officer is able to calculate the estimated time of arrival (ETA) to the next destination.
Furthermore, It is necessary to calculate other ETA for the passage in particular zones, like fog presence area, high traffic area, pirates danger and more.
Now the OOW (Officer of The Watch) is constantly responsible of track monitoring on board, not only with the electronic instruments like radar and ECDIS but also with the methods of traditional navigation like azimuth circle and sextant.
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