Many people at this time of year will be starting to use their boats having perhaps not used them since towards the end of last year. It is very easy to forget the ‘collision regulations’ that we must obey to prevent collisions with other vessels.

Some people reading this article will have completed an ICC course with me at some stage in the last few years, they too will perhaps at this time of year feel a little rusty with this part of the syllabus and I hope that this article will help to remind them of their obligations to other vessels.

Motor Boats, Jet Skis and Yachts when under engine

Give way to the right

The International Regulations for Preventing Collisions at Sea were written so that we can be completely clear as to what our obligations are to other vessels at sea, they are written very clearly and precisely so as to be totally unambiguous. Basically motor vessels, and this of course includes sailing vessels when they are under motor, should give way to other vessels that are approaching from their starboard side. When in a ‘head on’ situation both vessels should turn to starboard so as to pass port to port. When a vessel is overtaking another vessel the overtaking vessel should keep out of the way of the vessel being overtaken.

Pass port to port

There are just two situations that you can be in when there is a risk of collision. You will be either ‘the stand on vessel’ or ‘the give way vessel’. There are no circumstances when you can look upon yourself as having ‘the right of way’. In the event of almost inevitable collision the ‘stand on vessel’ has an equal responsibility to avoid collision as the ‘give way vessel’.

Motor Boats, Jet Skis and Yachts under sail

Take bearings

You may well ask as to how you are expected to know if a collision with another boat is likely. The answer is simple; you should have a good quality hand bearing compass with you, take a series of bearings of the vessel with which you feel you might be on a collision course, if the successive bearings remain the same, then you will definitely collide if the successive bearings increase or decrease then there is no risk of collision. The diagram above illustrates this theory well.

Vessel on the starboard tack is the stand on vessel

In a situation where you are ‘the stand on vessel’ you are expected to maintain your course and speed, however if the other vessel who falls into the category of ‘give way vessel’ does not give way as required by the rules then you must take action to avoid collision. This action will inevitably take place when you are fairly close to the other vessel and should be in the form of a manoeuvre rather than just an alteration of course. The manoeuvre that I would recommend would be a 180 degree turn away from the vessel and to maintain that course until the other vessel is clear.

At first when we look at collision regulations written out in full it is easy to feel a bit daunted by their apparent complexities, however they can be reduced to a few basic rules. You are either the Stand-On vessel or the Give-Way vessel. The Stand-On vessel is the one that, in a meeting situation with another boat, holds to its course and speed. The Give-Way vessel is the one that is required to take early and substantial action to keep out of the way of the Stand-On boat and avoid collision.

Motor Boats, Jet Skis and Yachts under engine

The area from dead ahead to 112.5 degrees down your starboard side is your danger zone. Any vessel approaching you in that zone is the Stand-On boat, thus making you the Give-Way boat. Also if you are overtaking another boat, you are automatically the Give-Way vessel.

We all know that motor vessels should give way to sailing vessels; however in confined and shallow waters such as Ria Formosa it is clearly out of the question to expect very large commercial vessels to give way to vessels under sail, it therefore makes sense for sailing vessels to keep out of their way. There is also a rule in the regulations that tells us to keep out of the way of larger vessels in a narrow channel. However out at sea off the Portuguese coast I would expect even very large ships to give way to sailing vessels and in most cases they do. It is in this situation that I have been on ‘both sides of the fence’.

Don’t give way just because it’s bigger than you and made of steel!

On the bridge of a ship the radar will be in use even in good visibility. The crew that are on watch will constantly monitor the radar which will keep them informed as to which vessels shown on the screen they are likely to collide with, if both vessels maintain their course and speed. Motor vessels, yachts under engine and ships that are approaching from the starboard side of the ship will be ‘stand on’ vessels as will all vessels under sail approaching from any direction other than from astern. Adjustments will be made to the course and possibly the speed of the ship to avoid collision with any ‘stand on‘ vessel, often this adjustment will be fairly small because the crew will be able to tell from the radar as soon as they have altered course or speed sufficiently to avoid collision.

Many inexperienced motor cruiser and yacht skippers have said to me that even if the other vessel is ‘the give way’ vessel, if it is bigger and made of steel they will give way to it. You can see that if you were the skipper of a ship in this instance it would be infuriating if a ‘stand on’ vessel were to alter course for you when you had just made the decision to ‘give way’ `to him. Not only is it infuriating for him, but it also very dangerous because if they both alter course to pass astern of each other they will alter course directly into each other.

Yachts under sail

The windward vessel must give way

Sailing vessels have an additional set of rules in order to avoid the possibility of collision with each other. These rules are also very straight forward and are as follows: A yacht that has the wind coming from its starboard side is the ‘stand on’ vessel when approaching a vessel that has the wind coming from its port side which is the ‘give way’ vessel. If both vessels have the wind coming from the same side, then the vessel that is up-wind of the other vessel is the ‘give way’ vessel. It is sometimes difficult when a yacht has the wind coming from almost directly astern to tell which side of the yacht the wind is coming from, in such a situation the wind is deemed to be coming from the opposite side to which the main boom is being carried.

Narrow channels

Passing port to port in the Olhão channel

Remember the following:

Start taking bearings early, make a decision and then if you have decided that you are the ‘Give-Way’ vessel make a substantial alteration of course to send a clear signal to the other vessel that you intend to give way. If you have decided that you are the ‘Stand-On’ vessel then maintain your course and speed.

Two motor cruisers on a collision course going towards each other, each travelling at 25 knots, from a point when they are two miles apart will take just 2½ minutes before they collide.

Two yachts going towards each other at 6 knots on a collision course from a point when they are half a mile apart will collide in 2½ minutes