Drift diving
Drift diving is a type of recreational diving where the diver is transported by the currents caused by the tide or in a river.
The current gives the diver the impression of flying and allows the diver to cover long distances underwater, possibly seeing more habitats and formations than usual.
Often drift diving is performed more for the experience of underwater "flight" and less for interactions with underwater life, which, given the speed at which most divers move, are reduced.
Tidal streams can keep an area free from sediment, increasing visibility.Normal precautions for drift diving are to have a supporting boat follow the divers and to use a surface marker buoy.Drift diving requires specialized training and certification to be done safely and properly. PADI Dive Centers with Open Water Scuba Instructors offer drift diving training as part of the Advanced Open Water Diver training, and is one of the specialties available therein.
Drift diving requires more rigorous planning to be executed safely.
In contrast to normal diving, drift diving is generally not planned to coincide with slack water.
It is important to consider the direction of tidal streams as well as their strength to avoid divers being swept into dangerous areas such as shipping lanes.
It is also important to plan for the danger of separation, either underwater or at the surface.
Each diver should carry an appropriate signaling device 
It is important for the diver to also have knowledge of the local rules pertaining to the use of surface marker buoys, as in some parts of the world, surface marker buoys alone are not legally sufficient signaling devices, and either of the international diver's down flags (in the appropriate size), or perhaps both, might be required while drift diving.
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.
