Flying with other pilots can greatly enhance your ability to map out a thermal and stay in the air longer. When you find yourself flying with a group, it is usually referred to as “gaggle flying.” Thermal flying will take some time to figure out, but if you find yourself in a thermal with other pilots, there are a few rules you need to know about.
The first pilot in a thermal establishes the direction of the turn. If you find the thermal first and you like right turns, by all means turn right. All pilots must turn the same direction. If somebody else is already in the thermal and turning left, you need to turn left as well. Again, lower pilots have the right of way. The pilot below has limited visibility above them and may not be able to see you. Even if you were the first person in the thermal, and they enter it turning the opposite direction, you will need to change direction to match theirs. As in ridge-soaring, the pilot below will encounter lift first so you should avoid flying directly over anyone. When joining another pilot at the same altitude in a thermal, enter tangentially to their circle. Don’t cut through their flight path. By entering tangentially, you can smoothly join the other pilot without disrupting their turn. You may join a thermal between two sets of pilots who, for whatever reason, are turning opposite directions. You should turn the same direction as the closest group, keeping in mind that the group below you can’t see up. Keep track of the pilots at your level. If you are in a “gaggle” of pilots you won’t be able to keep track of everyone, so focus on the nearest pilots. When flying with other aircraft, keep in mind the performance of each and respective visibility restrictions. This will help you decide how to interact with them. Paragliders will be the slowest, followed by flex-wing hang gliders, rigid wings, and sail-planes. Generally the slowest craft can turn the tightest and so will generally be at the center of the circle.