Risks when navigating in the archipelago with reduced visibility

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The Transport Agency takes up two cases of faulty navigation in the archipelago which underline the importance of knowing the navigation equipment on board well, keeping it in good condition so that it works correctly, and planning the voyage carefully, even if the crew are familiar with the passage and the surrounding area.

Case 1

In case number one, a small ferry went off course and ran aground in conjunction with ice, dense fog and darkness. Due to the icy conditions, two marker buoys disappeared completely; one had moved and another had lost its light. The magnetic compass on board could not be read from the control position and the electronic sea chart only showed the course over grounds. Once out in the fairway, the master turned to port to go clear. He then thought that he had stopped turning and continued on the new course, and the information he received from the radar confirmed that the course over the ground was in the right direction and the heading was good. A little while later the two courses started to diverge. The master checked the GPS, which showed that one course differed by approximately 35 degrees from the expected course. The master decreased the speed and at the same time saw that the ship continued to turn to port by about 10 to 15 degrees. The master then put in full reverse to stop the ship. By that time, treetops and a lighthouse loomed ahead of the ship and it went aground.

Case 2

The second navigation event took place on board a small merchant vessel that was sailing along a narrow passage on a sunny day in spring. The ship was bearing towards the south-east in the archipelago, and was on the way out of a sound. On board there was a combined electronic sea chart and radar display used for navigation. However, a complete voyage plan had not been made and when the master had the sun in his eyes, neither he nor the lookout man could identify the marker buoys and the ground that lay straight ahead. Since the master knew the area, after a while he slowed the ship and changed course, but by then it was too late and the ship ran aground. Another reason for the buoys not being noticed was that visibility through the cab’s plastic windows was poor due to the condition of the panes.

Both of these accidents could have been avoided if the navigation equipment available had been fully utilised. A proper voyage chart would probably have helped the master in the second case, and time should always be set aside before departure to plan the voyage and reflect on the risks in the waters the ship is sailing through. It is an organisational and safety culture issue which is becoming increasingly important to take into account, since electronic means of navigation are becoming commonplace and more advanced. This also applies to smaller vessels, where skills requirements and levels of training are not as extensive as for larger tonnage.

Connecting onshore power supply

Case 1

When a ship connected to the onshore power supply, there was a short circuit and an arc burned out both the glove and the plug, as well as blowing open the door to the booth housing the connection. Because the company had already experienced a similar event, there was a requirement that the connection station should be well protected and that the on/off switch for the current should be well separated from the connection itself. This proved to be a wise investment, since the flash-over was very powerful and could have given rise to a far worse situation if the person turning on the power had been near the connection. After the event the shipping company decided to further tighten the safety procedure by informing other ships of the event and always having qualified staff examine both the plug and the glove before making the connection. They also check that high current equipment is always kept in good condition when not in use, so that salt, moisture and dirt do not affect its operation. It has also been decided not to connect to an onshore power supply if the connection station is not of a sufficiently high standard.

Case 2

A ship which had been connected to an onshore power supply had a blackout in confined waters after departure. The ship was forced to make an emergency anchorage to avoid grounding. When looking for the cause, a circuit board was found that had been burned, probably in connection with a thunderstorm and lightning in the area where the ship had docked. This is an interesting conclusion, given that it has become increasingly common to connect with onshore power supplies even when making normal port stops for loading and unloading, when the ship’s own power supply was used in the past. If something similar has happened/happens on your ship, it is valuable for the Swedish Transport Agency to know about the event and its consequences – so please report any such incidents via the Transport Agency’s form for reporting shipping accidents, which is available on our website.


Also read the Transport Agency’s brochure ”Guidelines and recommendations for connecting ships and leisure boats to onshore power supplies”, also on our website.


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