Once you complete your open water diver course everyone remembers the number one rule of diving…never hold your breath! Not all of the rules or standards may stick with you throughout your diving career.
A rule of diving many may remember but are uncertain of its importance is to turn the knob back a quarter turn after turning on your air.
Why does this fall on the diver do list?
Regulators have a failsafe design. If your first stage fails it is designed to free flow. In a free flow situation where the tank is wide open a diver may not be able to turn off their air. The pressure of the air being released along with the pressure at depth may be too great; impeding the diver from returning the knob to the closed position.
An incidence such as this happening on a shallow dive should not be dangerous in theory. During entry level dive courses students conduct a controlled emergency swimming ascent. This skill places the diver at a depth between 20-30ft in an out of air or low on air simulation. The diver kicks to the surface in a controlled safe ascent of not more than 60ft a minute.
The key to this skill is the diver completing the safe, controlled ascent while slowing exhaling. Upon reaching the surface the student completes the skill divers by orally inflating their buoyancy control device (BCD) opposed to using their low pressure inflator.
An additional skill is to breath from a free flowing regulator. Student divers breath from their primary regulator while it is free flowing. This skill prepares divers for such experiences. Many first stage regulators that fail force the primary regulator to free flow.
Failure of a first stage during a deep dive purposes additional challenges. Dives conducted at 100ft or greater and dives that end within three pressure groups of your no decompression limit require a safety stop. In this instance we are not looking at a simple ascent to the surface. The diver has an obligation to stop between 15 & 20 ft. for three minutes.
Taking this into consideration the diver at hand and their buddy will want to preserve air. Conducting an alternate air source ascent-breathing from your buddy’s alternate air source- may not provide adequate air for both divers to conduct a safety stop. Having the ability to turn off the tank with the failing first stage can preserve the air until it is needed.
Depending on the comfort level of the diver, or their buddy, he or she may prefer to turn off the air of the said diver long enough for the diver to exhale while opening the tank long enough for breathes.
Failure of a first stage is a rare occurrence being the designs used today. However, keeping this in mind Do remember to turn your tank valve back one quarter of a turn when diving.
On the opposite side of the coin we have an act that occurs often while diving which falls on the diver don’t list. Dive gear particularly regulators, are not cheaply built or cheap to purchase. It is important to properly maintain your regulators not for longevity sake alone. This is the gear that transfers the air you breathe at depth from your tank to your lungs.
It is imperative to properly care for and maintain your regulators to ensure the air you breathe is pure. Diving with tanks filled from reputable air stations is not the only step to ensure the quality of air you breathe.
Rinsing the regulators after each dive, having your gear serviced annually, and proper storage is essential. A common mistake for novice divers is failure to place the dust cap prior to rinsing.
This diver don’t item takes it a step further. While breaking down gear post dive it is not uncommon to see novice divers place their first stage in front of their tank cracking open the tank allowing air to blast into the first stage.
Divers often use the tank to blast air into their dust cap for drying purposes prior to placing it over their first stage. The purpose of the dust cap is to protect the opening of the first stage. This prevents water, dust, etc. from entering the first stage.
Where does the problem lie with this method? Blasting air into the first stage post dive is not necessary as air is all that has travel through your first stage. Be doing so it may force peripheral water droplets into the first stage. Water inside the first stage can result in corrosion. This corrosion may reside deep within the first stage due to the pressure of the air used to blast the first stage.
If you rinse your gear without the dust cap in place have your gear serviced. Blasting the first stage alone is not the answer.
The dust cap is located closely to the opening of the first stage and water being blasted out of the dust cap may enter the first stage if it is not protected. Be careful with that one!