Regulator, Fins, Mask.
The next three items I’m going to cover, while super critical, are also super personal. To give some some perspective, I’m on my 4th regulator setup, 4th pair of fins, and 8th mask setup.
How does a regulator work? Typical recreational scuba divers breathe either compressed air (78 percent nitrogen, 21 percent oxygen) or an oxygen-enriched, nitrogen-oxygen combination called Nitrox (64 to 68 percent nitrogen, 32 to 36 percent oxygen). The gas is contained in a cylinder that you (typically) carry on your back. The typical cylinder is made of aluminum, weighs about 31 pounds (14 kg) empty and holds 80 cubic feet (2,265 L) of air at 3000 pounds per square-inch (psi), or 204 atmospheres (ATM). This volume of gas would approximately fill a phone booth and weighs about 7 pounds (3.2 kg).
You cannot breathe directly out of the tank because the high pressure would damage your lungs. Therefore, the cylinder is fitted with a regulator. The regulator does two things: It reduces the pressure from the tank to a safe level for you to inhale, and it supplies air on-demand. To accomplish these tasks, regulators have two stages:
- First stage - The first stage attaches to the cylinder. It reduces the pressure from the tank (3000 psi or 204 ATM) to an intermediate pressure (140 psi or 9.5 ATM).
- Second stage - The second stage is connected to the first stage by a hose. It reduces the pressure from the intermediate pressure to ambient water pressure (such as 1 to 5 ATM depending upon depth). The second stage also supplies air, either only when you inhale (typical operation) or continuously (emergency operation).
My current regulator setup is a ScubaPro MK25 First Stage, and a700 Second Stage. This regulator breathes really easy, even under hard work conditions (upside down, heavy current, deep depth) and is made for both cold and warm water. When tropical diving I like to reduce drag as much as possible. So I’ve lost the traditional backup octo (Backup regulator) and instead have a backup that is attached to my BC inflator. I use a 7′ Miflex hose to connect the 1st and 2nd stage. My AI (air integrated) transmitter attaches to the HP port on the 1st stage, sending tank metrics to the ICON computer. Last, I use a SeaCure custom mouth piece.
I’ve learned over time that the needs for cold water diving VS tropical diving require different fins. My cold water fins are ScubaPro TJM’s (Twin Jet Max). They are heavy (IE not travel friendly) and do a great job getting you moving in cold water when you’re wearing 40 LBS of lead. I’ve taken them tropical diving, and they do OK.
My tropical fins are much lighter and longer then the ScubaPros. Aqua Lung makes a fin called the Slingshot. They are an interesting design, with a joint in the fin that uses heavy/thick rubber bands to help convert your kick into forward energy. I really like them in tropical water, but fear they wouldn’t cut it in cold water.
I travel with a primary and backup mask. Many times someone on the boat has forgotten their own mask, and being able to hand them your backup saves their dive! Masks are sort of like sunglasses for me. I’m always looking, and interested in trying out new ones. Currently my primary mask is a Cressi Big Eyes Evolution Crystal. It’s low volume, has nice seals/skirt, and comfortable on my face. That last part is important. Above all else, you are looking for comfort in a mask. My backup mask is a Cressi Matrix. It’s an older model than the EVO, and almost as comfortable. The silicon on it is showing its age, so I’ll be looking for a new primary soon, putting my EVO as the backup.