Lane etiquette rules from USMS article
“1) (This is applicable to many advanced swimmers) if you are circle swimming with other people in your lane pay attention to where you push off the wall when you flip-turn. Envision yourself swimming down the right side of the lane, with another swimmer five seconds in front of you. If that person swims straight into the wall and flips such that her feet push off the right side of that big black cross, she will have to cut a very sharp angle to gracefully end up on the other side of the lane. She will narrowly miss crashing into you with each turn. If, conversely, she angles left into the wall, and pushes off to the left of the black cross, she can then streamline straight off the wall and is automatically on the correct side for the return lap. No near crashes. No need for you to give her ten seconds of lead time. 2) If you are slower than anyone else in your lane, you must always yield to them. Never ever begin your lap as they are approaching your wall for a flip turn. Let them go first. If you notice that they are normally doing freestyle but end up stuck behind you and start doing breaststroke to slow down, you need to let them pass at the next turn. Remember that for many people this is their gym and you’ve just turned their stair-master down from a level 12 to a level 3.
3) When you need a rest break, don’t stand at the end of the pool in the middle of the lane. Other swimmers need to use the wall for flip turns. To take a break, swim into the wall on the right side, and stay as close to the lane line as possible.
4) If you are doing a set with a group of more than three people, pay attention to the person behind you. With three people, each person can touch the wall at the end of the set and look up to see his or her time. With four people, the third swimmer needs to move away from the wall so that the fourth person can touch the wall at the end. Usually the way this works is at the end of a set the first person touches in on the far left side of the lane. The second person touches in the center, and remains there. The third person touches to the far right, and then immediately moves to the center of the lane, no longer adjacent to the wall, so that he is pool-side of the second person. Now the fourth person can touch in on the far right. This seems complicated, but I’ve swum with upwards of 10 people in a lane, and it works if everyone plays along. With more than four swimmers, each additional person needs to move to the center of the lane after they touch in on the right.
5)By all means don’t “borrow” your lane mate’s fins/kickboard/pullbuoy without asking.
With any luck, by following these rules a new swimmer can become a happy and productive member of our aquatic society. “
And 6) Tap the person in front of you on their feet to let them know you will be passing them up at the wall.