You may have seen these humorous guidelines or a version of them over the years. The original author is unknown, but the point they make is a valuable one.
If you’re planning a trip, you might want to distribute a copy of these to the divers who will be on that trip.

It’s a light-hearted way to remind them to "keep cool" when the inevitable glitches and unexpected problem arise during a trip.

1. Do not expect to find things to be like at home. You left home to find things different.
2. Do not take anything too seriously. A carefree mind is a vital to a good vacation.
3. Do not let other travelers get on your nerves. You paid good money to enjoy yourself.
4. Do not forget: you are a representative of your country at all times.
5. Try not to worry because he or she who worries will have no fun. Remember that few things in life are fatal.
6. Know where your passport is at all times because a traveler without a passport is a traveler without a country.
7. As a stranger in a strange land, be prepared to do as its people do.
8. Do not judge all people of a country by the one person who has given you trouble.
9. Learn how to say thank you in the language of the country you’re visiting. A sincere thank you, along with a smile, doubles the value of any tip you may give.
10. Remember that you are a guest and those travelers who treat their hosts with respect will be treated likewise.