It must be a culture thing but they just don't wave. No worries.

I'll admit that I don't always stick to a rigid 'follow the rules' policy. If a guy is under spinnaker and I see that we'll be close but I have the right of way I'll alter course and fall behind him. The same in tight quarters with a boat working it's way windward and I'm off wind taking a leisurely pace. It's when someone isn't paying attention, is really motorsailing or hasn't a clue and continues on in what will ultimately be either very close or a collision is the one that I like mess with. I'll hold my course just watching him as we approach each other hoping that he'll figure out the proper action for him to take. Usually, if I do 'stand on' when my vessel has the right of way a collision is avoided because eventually the other captain either starts paying attention, figures it out or alters course, goes home, reads the rules and understands what took place. If I alter course even a little, the next time the other skipper is in the same situation he'll be just as oblivious as he was the last time, or worse yet, become even a lazier sailor.

Being nice and helping out another skipper by altering course when he's the one that should alter course 'according to the rules' doesn't help him learn anything and may in fact cause him to be even a lazier or a more self centered boater thinking the world revolves around him. That can't happen on the water. Everyone must pay attention at all times and know the rules

OK, I'll alter course without saying a word but their must be a reason. A guy that's just sailing along oblivious, not caring or masking the fact that he's under power by having sails up is who I hold course for. Always watching to make sure rule #1 (avoid a collision) is primary to me.