ScubaFeenD
Contributor
No need to be insulting. The OP's assumption was not off the mark. While the long hose configuration is now widely used for open water diving (by those that use them that is), it was originally designed for air sharing in restricted environments.
If the OP scrolled down and spent and extra 10 seconds on the page he would have found this:
"Restrictive areas, like caves, often require that divers travel single file. This means that unless divers are equipped with a long hose second stage, in the event of a failure, they will be unable to effectively share air in such an environment. The use of the long hose was primarily designed to manage air-sharing problems in restrictive areas, and has been a standard feature of cave diving for many years. Anytime divers are forced to travel while air sharing, using the long hose is mandatory. Furthermore, divers facing decompression will use a long hose. Today, many open water divers also choose the long hose because of the comfort it provides during air-sharing situations. Properly trained and equipped divers often dive with a long hose; this allows them greater flexibility while diving. The backup regulator hose should come across the diver's shoulder, allowing the regulator to sit below the chin without the hose bulging to the side.
Diving in a shallow, open water environment allows a diver direct ascent to the surface, thereby reducing air-sharing complications. In this case, divers will sometimes use shorter primary regulator hoses, an acceptable practice in this environment. Obviously, such an event is only for emergencies. Divers ascending from SCUBA on a breath-hold must exhale during the ascent to prevent embolism. This technique should be practiced and discussed during open water training. "
Really, is it that difficult for divers to read and find their own answers before starting a thread to clarify confusion?