SmokingMirror
Contributor
NauticalbutNice:Also, in Scotland, tips (Except in restaurants/cafes/taxis etc.) is seen a bit weird.
...as it is in most of Europe. A tipping culture is just one of the many reasons why many Americans are so easily parted from their money whilst abroad.
However, and in answer to the original question, the situation is slightly different when diving in the US, where tipping has transcended its original point into an expected social norm.
As to tipping an instructor: If you're prepared to tip everybody else for services rendered, why not the instructor as well? As someone else has already and quite rightly mentioned, the instructor is the one making themselves liable for your personal safety whilst you are under their supervision. Some might say that that level of responsibility merits some kind of gratitude.