• Phone: 702-591-0593
  • E-mail: Dave@doalasvegas.com 
  • SCUBA FAQ

    How much does it cost? To find the cost and requirements for all scuba training offered by Dave’s Outdoor Adventures, go to the Scuba Training or price list section of this website or call 702-591-0593.

    If I start right now, can I be done by tomorrow afternoon? If not, how long does it take? No.  You can’t be done by tomorrow afternoon.  The certification process has four phases; home study, classroom, pool, and open water. The first phase is the home study phase. During the home study, you work at your own pace to watch a video and read the Open Water Manual.  Once that is complete, we move to the classroom phase.  Classroom consists of 8-12 hours of classroom time, usually split over two days. Next comes the pool. In the pool, we spend 3-5 hours practicing the basic scuba skills. Finally comes the open water.  Open water consists of at least five dives over two days.

    I’m terrified of the water.  I don’t even take showers.  Do I actually have to go under water to get certified? Yes. If you’re that afraid of the water, you might consider an activity that’s less . . . wet. I recommend you work on the shower issue. I’m sure anyone who has to be near you would appreciate it.

    What do you see when you dive Lake Mead? Diving Lake Mead is underrated. There’s lots of color. It’s all brown, but there’s a lot of it. Seriously, Lake Mead offers some of the best fresh water diving available. There are a few boat wrecks, lots of interesting terrain, and a few artifacts left over from the construction of Hoover Dam.

    How long does an air tank last? That question is impossible to answer without more information.  Air goes faster as you go deeper, you breathe more if you’re working hard or if you’re cold.  Air consumption varies from person to person. Women usually use less air than men. There’s just no easy answer. Generally speaking, an 80 cubic foot tank (most common) will last a new diver about 20 to 30 minutes at 25-30 feet.  With time, that gets better. Outside of class, my dives are usually an hour or longer. In order to calculate how long a tank will last, you must know your SCR (surface consumption rate).

    What is SCR (surface consumption rate)? Surface consumption rate is the amount of air you breathe over a given time at the surface. Before you can calculate your SCR, you will need to make a few dives to gather the required data.  The formula is ((PSI used / time underwater) X 33)/ (average depth + 33).  This calculation will tell you how many psi/minute you breathe on the surface.  To convert psi/min to the more useful cubic feet/min, divide the tank size by the rated pressure then multiply that by the results of the previous calculation.  Example:  You did a dive with an average depth of 40 feet for 50 minutes.  You used 2500 psi out of an aluminum 80 (the tank holds 80 cubic feet at its rated pressure of 3000 psi).

                       PSI used = 2500      Time underwater = 50 minutes         Avg depth = 40 ft

    SCR = ((2500 psi/50 min) X 33)/(40 ft + 33)

    SCR = (50 psi/min X 33)/73

    SCR = 1650 psi/min / 73

    SCR = 22.6 psi/min

         On that theoretical dive, you used 22.6 psi per minute. Now let’s convert that to cubic feet per minute.

    CF/min = SCR X (Tank size/rated pressure)

    CF/min = 22.6 X (80/3000)

    CF/min = 22.5 X .0267

    CF/min = 0.6

       According to our calculations, you would use 0.6 cubic feet of air per minute on the surface.  As you to deeper, the air goes faster. To calculate how long the air would last at depth, use the following formula:

    Consumption rate at depth = ((depth/33)+1) X CF/min

         At 60 feet: ((60ft/33)+1) X 0.6 = (1.82 + 1) X 0.6 = 2.82 X 0.6 = 1.692 cubic feet per minute. That means, if your SCR is 0.6 and you go to 60 feet on an 80 cubic foot tank, the tank will last 47 minutes.  However, the tank would be completely empty at that point.  It will last 39 minutes leaving 500 psi in reserve.

    Aren’t you sorry you asked?

    What is the most terrifying thing you’ve ever seen underwater? My ex-girlfriend.