Overlaps - difficult
Often a “technical” overlap is established ie bow overlaps rudder. The boat coming from astern cannot run into the transom as they have to avoid contact If they go to leeward of the transom due to overtaking too quickly they need to be careful to leave sufficient space for the corner of the transom to move as the windward boat responds.
If the “technical” overlap lasts for any length of time one begins to expect a response from the windward boat, and there is usually a distance of some 1-2 ft that the transom can move without there being contact between the rudder of the windward boat and the bow of the leeward boat. There will be less than 6inches between the bow of one boat and the stern of the other, but this will be irrelevant as they are travelling at about the same speed.
This is where the judgement come in – at what point are you convinced that an overlap has been clearly established and how much of a reaction should you expect from the now windward boat.
They are closer to the action and should be sable to bring the rudder to within 6inches of the leeward boat. Doing nothing by the windward boat is not an option.
The time-scale is really difficult, less than a second and one expects to see a response appropriate to the gap between the bow of one boat and the rudder of the other. How close is too close? Nothing is immediate – it is a judgement
Particularly when the boats are snaking.this can happen again and again and in small boats the wing is rarely in position to see the overlap precisely. It is hard work,and being consistent is not easy.