All around the world the rules of surfing are the same. These rules are known as "surf etiquette". Some breaks (or great surfing locations) have the surf etiquette on signs or plaques displayed prominently before you get in the water. In this day and age of increasing "rage" with everything, there is surf rage as well.
Be respectful of the universal surf etiquette code to save yourself many unpleasantries. No one wants to wear a surfboard in the face. No one wants to wait ages for the perfect wave to have to get off to prevent themselves plowing into someone dropping in or not knowing what they are doing. No one wants to be beaten up in the parking lot for infuriating a local by dropping in (see below for definition) on their wave. No one wants to get their surfboard dinged by some novice who doesn't know what they are doing. No one wants to go to prison for committing surf rage, either.
The rules have been invented to try and keep everyone safe, and also to make it fairer. Some surfing breaks enforce the rules more than other places. If you are at a new break take a minute to observe the locals.
Right of Way. The surfer on the wave who is closest to the breaking edge has right of way. This means that the wave is theirs. Unless they fall off their surfboard, or pull out of the wave, they have priority, or right of way. To put it simply, if there is already a surfer on their feet on their surfboard closest to where the wave is breaking, you can't surf that wave. The wave is already taken.
Dropping In. Never, ever, drop in on another surfer's wave. This is considered the most heinous of surfing crimes. If there is someone on the wave already you cannot just hop on the wave in front of them. This is what is known as dropping in. Committing this surfing crime could result in your surfboard being banged up, the other surfer surfing over the top of you, the surfer having to pull off his wave, causing major fury, and more often than not, you having to endure surf rage. If you do not want to be abused physically or verbally do not drop in on another surfer, ever. When you drop in on another surfer all the other surfers can see you and they will all have a terrible impression of you. There is no excuse, ever. Dropping in on another surfer has resulted in flat tires, broken windscreens, and in some locations in Australia, the perpetrator's surfboard has been smashed and hung from the highest tree.
Getting Back Out. When you are paddling back out to the break (where the good waves are), you need to keep out of the way of surfers. Other surfers do not want to lose their wave so as to not ride their surfboard over the top of you. You need to paddle behind where they are surfing and not get in their path. You will be paddling through more white water, but everyone has to do it.
Sharing. Some surf breaks have more aggressive local surfers than others. Locals have a right to surf their own break. Visitors should respect any local customs as well as the universal surfing etiquette. Visitors are entitled to surf the waves as well, but care should be taken to not antagonize the locals. Sharing and respect will result in you being accepted by the locals and having a more pleasant surfing experience.
Control Your Surfboard. An out of control surfboard can create a lot of damage, both to yourself, other surfers, and their surfboards. When you are paddling out to the break you need to hang on to your board. This is for 2 reasons. Firstly, so as you don't injure anyone paddling behind you, and secondly, you will get out the back (where the good waves are breaking), quicker if you maintain control of your surfboard. You will only be forgiven for letting go of your surfboard if it looks like you will meet your death being wiped out otherwise. Only self centered dorks ride a surfboard without a surfboard leash in crowded environments. Remember, respect in the water goes a long way. Treat the other surfers how you would like to be treated yourself.