May 9, 2013

Safety on board: avoiding ships

Discussion has lately been vivid on the subject of sailboats vs. ships on various internet's sailing forums. Locally, we had a recent court case where two skippers of yachts, participating in the sail race, were fined for steering their boats too close to the 250 meters' long tanker ship. More serious incident happened in UK during the Cowes Week 2011, when a yacht, participating in the regatta, actually collided with a tanker. Yachting Monthly wrote on their May issue about the incident, where luckily were no casualties. Check out this following video of the incident:

These two cases, and the discussion around them, made me revise the COLREGs (Collisions Regulations) and re-think our routines for avoiding ships. After all, a collision with a ship is one of the most serious incidents, which can happen at the sea.

It seems to cause controversy whether a sailboat is a give-way or a stand-on vessel in respect to the ship. By the way, COLREGs do not give a right of way to one vessel over another; the stand-on vessel has to keep a steady course and speed and be ready to take action, if the action taken by the give-way vessel is not sufficient to prevent collision. As a general rule, a powerboat gives way to a sailboat. However, there are exceptions to this rule if the former has a restricted maneuverability. Following is the order of increasing maneuverability; a boat lower in the list has to give-way to the vessel higher on the list (source
  1. a disabled boat
  2. a boat that is difficult to maneuver, like a dredge or barge in tow
  3. a boat whose maneuverability is restricted by size or draft, like a freighter
  4. a boat engaged in commercial fishing, like a trawler
  5. a boat being rowed
  6. a sailboat
  7. a recreational powerboat
When talking about the large ships, it is good to presume (also by common sense or self-protection instinct) that they have restricted maneuverability due to their size, and thus a sailboat is a give-way vessel in respect to the ship. This is especially true in shallow and narrow waterways of the Baltic Sea archipelagoes.

M/S Queen Elizabeth in Stockholm Archipelago
However, in practice the situation is not always as simple as that, since in offshore it is often the case, that ships do alter their course several miles in advance to avoid a crossing course with a leisure boat. Therefore, it is important to monitor if the ship has already taken actions to avoid you. Inexpensive AIS-receiver is particularly handy in this, since it has information on the speed and course of the ship.

A fishing trawler in Skagerrak
When visual, AIS or radar contact is made of the another vessel, it is important to assess the risk for collision before taking any significant action. In addition to the radar and the AIS-device, a bearing compass is helpful tool: it is good idea to take a bearing of the ship, when you see it in the horizon and monitor changes. If the bearing remains the same or changes very slowly, you are probably on a collision course.

There was an interesting story also in the May issue of the Yachting Monthly about collision between a 50ft sailing yacht Whispa and a freighter Gas Monarch in 2007 in UK waters. Due to the dense fog and misinterpretation of the radar image on the location of the ship, the sailboat altered her course 50 degrees to starboard which actually put the vessels onto a collision course. Without (mis)use of radar, the vessels would have passed each other within a good distance. Thus, actions based on a imperfect knowledge may lead to a worse situation, than keeping an initial steady course. As always, there were many contributing factors to the incident  the complete report is available at

When it is assessed that vessels might be on a collision course, and you are a give-way vessel, it is important to make an early and significant alteration to your course to clearly signal for the other vessel your intentions. Course change should be merely several tens of degrees  preferably 60 degrees or more. If still  after the course change  the situation seems unclear, it is wise to call the ship's bridge by VHF to discuss how the situation is handled. AIS receiver is handy in this situation as well, since it usually shows the name and the MMSI-number of the ship, so you can call it by the name. Even better, if you have a VHF-radio with a DSC-function: you can then contact the ship directly.

AIS receiver is handy in monitoring ships

As a conclusion, it is also good to keep in mind that ships do not always keep a proper lookout and the radar does not see everything. Therefore, a good supposition is that the ship does not see you. Also if crossing a busy shipping lane, the crossing should be made as close to the 90 degrees angle as possible.

So far the busiest shipping area, that we have experienced, was in the Southern Baltics near Bornholm. However, I guess that the North Sea and especially the English Channel are much more challenging in this respect. I have mostly written about good weather conditions, but poor visibility makes the life a lot more complicated. What kind of experience and tips do you have about avoiding ships?

Morning rush hour in Stockholm Archipelago

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It would be very great to hear your opinion or comments. Thank you in advance for commenting! -Antti & Minna