Whatever their size or type, all skippers have a responsibility to avoid collisions with other boats at sea.  It is important for all boat skippers to know the give-way hierarchy at sea to help avoid accidents. But how similar are the rules of the road on land and at sea?

On land, road users have signs to show them the way and warn them of hazards they are approaching.  They avoid collisions with others by following the road rules.  They use light and sound signals to indicate what their intentions are. 

Broadly speaking, all this happens at sea too.  There are navigation marks which act like road signs; there are road rules to prevent collisions and there are sound and light signals to tell others of a vessel’s intentions.  In addition there are some extra factors to get to grips with:

• As there are no roads on the water, boats tend to move around in all directions. 
• There are more diverse shapes and sizes of vessels on the water than there are vehicles on land.
• There is a give way hierarchy between the types of vessel, which needs to be followed by all boat users.
• Vessels display lights at night to tell others which direction they are moving in and what type and size of vessel they are.
• Vessels display shapes during the day to tell others what type of vessel they are and certain activities which they may be involved in. 
• There are navigation marks which identify safe water channels and hazards to be avoided.
• There are light beacons which guide vessels safely towards land and into harbour at night.

Learn all of the nautical ColRegs Rules of the Road for power boating and sailing, in our comprehensive reference app, which includes a quiz to test yourself!

The give way hierarchy

If you are in charge of a boat you need to know what to do in a potentially dangerous close quarters situation and act accordingly.  It is important to know the ‘who gives way to whom’ hierarchy and this should be learnt by all boat operators.

Sailing boat hierarchy

Port tack gives way to starboard tack.

If on the same tack, the windward boat gives way.

If it is unclear to a sailing boat on port tack which tack another sailing boat to windward is on, then the boat on port tack must give way.

Power boat hierarchy

If two power boats are heading towards each other, both boats should alter course to starboard, so their port sides will pass each other.

If two power boats are crossing paths and there is a risk of collision, then the vessel which has the other on its starboard side must give way.  It must also avoid crossing ahead of the stand-on boat.

Narrow channels

All boats should keep to the right of narrow channels. Vessels of less than 20 metres in length and sailing vessels must stay clear of larger vessels who can only navigate within the channel.  It is often the case that smaller craft can operate safely outside a buoyed channel.

Give-way vessel

When two similar vessels are crossing, the one that has the other to its starboard side is the give-way vessel.

The ‘give-way’ boat is responsible for keeping clear and altering course where necessary to avoid a collision. The give-way boat should make an obvious course direction in plenty of time, so the stand-on vessel is in no doubt it has taken avoiding action.

Stand-on vessel

If you have the right of way you are the stand-on boat, keep to your course and speed to make it easier for the give-way boat to manoeuvre out of your way. If the give-way vessel does not take avoiding action, the stand-on vessel must be ready to turn quickly out of the way or stop as a last resort.

Overtaking

All vessels, whatever their size and type, must keep well clear of others when overtaking.

A vessel is said to be overtaking another if it is approaching more than 22.5º behind the other vessel’s beam.  This overtaking sector covers an arc of 135º, which is the same as the arc of a stern light.  At night, it is easy to tell if you are overtaking a vessel because you can see its stern light as you approach it. 

During the day, it is not always as easy to be sure you are in the overtaking sector.  Are you overtaking or alternatively are you crossing the other vessel’s path, in which case you could have right of way? If in doubt, it is always best to proceed with caution and keep well clear of the other vessel. 

Learn all of the nautical ColRegs Rules of the Road for power boating and sailing, in our comprehensive reference app, which includes a quiz to test yourself!