Drift diving is a popular form of diving which is defined not by equipment or technique, but by location and water currents. In most open water diving situations the scuba diver propels himself by swimming and kicking the fins. In drift diving the diver descends into water with a known current and after obtaining neutral buoyancy lets the current carry him along.
Drift diving is arguably the most relaxing and pleasant diving experience there is. Because the diver is not exerting himself by swimming, he uses less air and thus can stay submerged longer on a single tank. Many popular drift diving reefs have currents which run parallel to the reef; once submerged the diver relaxes and watches the scenery float by; using only minimal effort to stay neutral and navigate around formations.
The whole point of drift diving is to “go with the flow” and not to swim against the current. The movement is often so gentle that divers don’t realize how powerful the current is; but they may soon realize its force when trying to swim against it! With a group of divers swimming into the current differences in swimming strength and fitness quickly become apparent since some divers swim easily upstream while others struggle to keep up. Going with the current a large group of divers can stay together very easily. Regardless of fitness level or swimming strength swimming against a strong current will use more air and the exertion of fighting the current abbreviates the diving experience.
Drift diving is almost always done from a boat drop-off. Do not anchor a boat and jump in – you must have someone on board to follow you. Once you begin drifting you will be carried quickly away from your drop-off point – often much more quickly than you realize or expect. It is very important for the boat captain to know which way the current is flowing and follow you from above. In calmer water (especially with larger groups of divers) the boat captain can see your bubbles and follow them. It is a very good idea for one (or more) of your group to have a signal flag or inflatable marker tube, on a reel, that you can send up when you begin to ascend – the boat will see it and approach to pick you up.