Showing posts with label Learn to Dive. Show all posts
Showing posts with label Learn to Dive. Show all posts

December 04, 2012

Diving Tips: Saving Air

Do you breathe your tank down faster than your buddy? Here are 5 diving tips to help conserve your oxygen and extend your bottom time.

1. Fix the small leaks
Even a tiny stream of bubbles from an O-ring or an inflator swivel adds up over 40 minutes, and may be a sign of more serious trouble ahead anyway. A mask that doesn't seal is another kind of leak in that you have to constantly blow air into it to clear out the water. It's also a source of stress, which needlessly elevates your breathing rate and thereby reduces your breathing efficiency. Does your octo free-flow easily? That can dump a lot of air quickly. Detune it or mount it carefully so the mouthpiece points downward.

2. Dive More
Inexperienced divers are famous for burning through their air supply at a furious rate, so one of the best diving tips for saving air is to simply dive more often. You may not be a new diver, but unless you dive almost every week it's still an unnatural activity. By diving more, your body will get used to the idea, and you'll breathe less.

3. Swim Slowly
The energy cost of speed is even more than you might think:  Swim half as fast as you do now, and you'll use less air.

4. Stay Shallow
Because your regulator has to deliver air at the same pressure as the water, a lungful at 33 feet (two atmospheres) takes twice as much out of your tank as does the same breath at the surface. At 99 feet (four atmospheres) it takes twice as much as at 33 feet. There's absolutely nothing you can do about that except to avoid being deeper than you have to be. If you're making a transit over an uninteresting sand flat to get to the edge of the drop-off, do it at 15 feet instead of at 40 feet, and you'll save air.

5. Minimize the Lead
If you're overweighted, you have to put more air into your BC to float it and be neutral. The inflated BC is larger and requires more energy and oxygen to push it through the water. An extra eight pounds of lead means your BC is one gallon bigger when inflated enough to make you neutral. 

Source: scubadiving.com

Diver Down Flag

You must have seen this little flag. In each boat diving is definitely attached flag. Now the picture is actually installed in the central office or at the dive services workers diving uniforms. If you are a fan of rock music Van Halen, in 1982 this band uses this logo on the cover of their album titled Diver Down.

What is the diving flag? Here's the explanation:

A diver down flag, or scuba flag, is a flag used on the water to indicate that there is a diver below. In North America it is conventionally red with a white stripe from the upper left corner to the lower right corner. Internationally, the code flag alfa/alpha, which is white and blue, is used to signal that the vessel has a diver down and other vessels should keep well clear at slow speed.

Purpose
The purpose of the flags is to notify to any other boats to steer clear for the safety of the diver and to avert the possibility of a collision with the dive boat which may be unable maneuver out of the way.
The use of the red and white flag, which was designed and introduced in 1956 by Navy veteran Denzel James Dockery, is required by law or regulation in many US states and Canada, as well in several other countries in the world (e.g. Italy). Usually the regulations require divers to display the flag and to stay within a specified distance of it when they are near the surface. As well there is often a larger zone around the flag where no boats are allowed to pass. Some states also prohibit the display of this flag when there is no diver in water. It can be placed on a boat or on a surface marker buoy.

Signal flag ALFA/ALPHA
As a code signal the International maritime signal flags A (letter ALFA/ALPHA) has the meaning of "I have a diver down; keep well clear at slow speed", used to indicate the presence of a diver in the water, and is more commonly employed in Europe and the British Commonwealth, including countries such as United Kingdom, Ireland, Australia, Canada, New Zealand, South Africa, and Kenya. It is also used by Russian Navy for the same purpose.

A rigid replica of the 'A' flag is required to be displayed by any vessel engaged in diving operations, when restricted in her ability to maneuver, if the size of the vessel makes it impractical to display the shapes and lights required by the International Rules for Prevention of Collisions at Sea (IRPCS) Rule 27.Although the presence of the 'A' flag may afford some protection for divers in the vicinity of the vessel displaying the flag, the intention of the rigid replica required by IRPCS Rule 27 (e) is to warn other vessels of the danger of collision. This marks a distinction between the 'A' flag and the red and white diver down flag
 
Other Use
Today the red and white flag is so strictly associated with scuba diving that it is also used to indicate a place where there are services for divers, for example stores selling or renting diving equipment or scuba service stations. It may be seen on the windows or bumpers of cars belonging to divers.