A post on another site recently .
yacht running down wind on a Starboard tack converging with a yacht on his starboard side on a port tack who has right of way ?

I thought it was green gives way to red be it under sail or power.

lydia said..
Not so quick Rule 13 overrides Rule 12.
So need more facts

Exactly, like whose boat is bigger

Most people don't even know rule 13 exists.

A few years ago there was a **** fight in a ocean race in respect to an after sunset incident as the Col Regs not RRS applied.

As I understand it, if neither boat is coming down on the other from behind (ie overtaking), then boat on port tack gives way to boat on starboard tack. If one boat is coming down on the other from behind (more than 22.5 degrees abaft of other's beam) then it must avoid whether it is on port or starboard tack. If neither can decide, then both must take whatever avoiding action is necessary and do so in a way that is clear to the other vessel as to what course alteration they are making, in good time. If necessary, they can signal their course alteration with noise (horn or whistle blasts) or light flashes (rule 34). Other than that, the colregs don't base right of way on a description of who can see which coloured light on the other boat - even tho' that may be how you spot the other boat at night.

MAGNESIUM said..

Quixotic said..
As I understand it, if neither boat is coming down on the other from behind (ie overtaking), then boat on port tack gives way to boat on starboard tack. If one boat is coming down on the other from behind (more than 22.5 degrees abaft of other's beam) then it must avoid whether it is on port or starboard tack. If neither can decide, then both must take whatever avoiding action is necessary and do so in a way that is clear to the other vessel as to what course alteration they are making, in good time. If necessary, they can signal their course alteration with noise (horn or whistle blasts) or light flashes (rule 34). Other than that, the colregs don't base right of way on a description of who can see which coloured light on the other boat - even tho' that may be how you spot the other boat at night.

I have read that the vessel on port tack should assume the down wind vessel is on starboard tack..
where I get confused is the down wind vessel classed as being upwind so have to give way or does his rights remain because the other vessel is on port tack.

Hiya Mag,
Hope this helps, refer to Figure 5. The red boat must give way to the green boat.