Now that all the calculations for course and distances have been covered, the last thing that needs to be included in the navigator’s arsenal is the ability to give an accurate Estimated Time of Arrival (ETA) at the destination. In addition, there will be times when the time of arrival is not suitable for the Pilotage and Harbour Authorities. It may well be that there is another vessel on your allocated berth at the same time as your given ETA. Pilotage operations at some ports could possibly only be made under certain tidal or weather conditions. This could mean that the vessel will have to anchor and wait until pilot or berth is available which could cause a lengthy delay. To avoid this, it is important to get an ETA prepared as soon as possible after the last Departure port, and forwarded to the destination port well in advance. The shipping business depends on co-ordinating services to maximise profit for each stakeholder.