Spartan SCUBA
SCUBA diver to instructor, we are your one-stop SDI, TDI, and First Response 5-Star Professional Development Center. Your adventure awaits! USMC veteran owned. #SpartanSCUBA
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CPR/AED Official!
It’s official: Spartan Scuba is now your local resource for all of your first aid training needs!
Nitrox Decisions.
Trying to figure out if you should take the SDI Computer Nitrox or TDI Nitrox course? Help is here!
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Dalton's Triangle
Dalton’s Triangle can be used to calculate everything from the best Nitrox mix for a dive, your MOD for a particular gas mix, or even the partial pressure of a gas at a given depth and Nitrox mix. This is one of the most imprtant tools in your dive kit!
MOD: Maximum Operating Depth
Using the triangle above: MOD is simply dividing your desired max Partial Pressure (typically 1.4) by your percent O2 as a decimal: 32% = 0.32, for example. This results in a pressure P of 4.37. Subtract one atmosphere for everything above water = 3.37, then multiply that by the weight of water: 33 for salt water, 34 for fresh. The result?, 111 feet of salt water.
Remember, always round DOWN your end result for depth!
Best Nitrox Mix
In order to calculate your best gas mix for a given depth you first need two things: your desired PPO2 (top of the triangle), and your desired P-pressure. Since we don’t talk in terms of pressure, but instead “depth” we need to first convert depth to pressure.
Pressure (P) = (D) depth/33 + 1 (atmosphere above water).
Once we determine our P-pressure, we can plug our numbers back into Dalton’s Triangle and calculate our best gas mix, let’s say for a desired PO2 of 1.5, this time (aka: ‘travel gas’).
Since we are now looking for the bottom right corner of the triangle, FO2, or fraction of O2, our equation would look like this:
FO2 = PO2/P :: FO2 = 1.5/5 :: FO2 = 0.3, or 30%.
You can do it just as easily for a sport dive mix of 1.4 PO2.
FO2 = 1.4/5 = 0.28, or 28% Nitrox!
EAD: Equivalent Air Depth
EAD=((%N/0.79)*(D+33))-33
%N is the percentage of nitrogen in your Nitrox mix. For example, if you are diving 32% Nitrox you have 0.68 N2. Replace %N in the equation with 0.68
D is the depth you dived to, or are planning to dive to.
- Step 1: divide your %N by 0.79.
- Step 2: add 33 to your depth.
- Step 3: multiply the results of steps 1 and 2.
- Step 4: subtract 33. This is your Equivalent Air Depth for your Nitrox mix.
Convert Bar to PSI
bar to psi: psi/14.7 = bar
psi to bar: bar*14.7 = psi
Temp to PSI
There are two methods of calculating temperature impact on tank pressure. The first is what I call the “cheater” method:
Cheater T to V: 1°F=5 psi 1C=0.6 bar
In other words, for every degree of Fahrenheit, the tank pressure changes by about 5 psi. Similarly for every degree of Celsius the tank pressure changes about 0.6 bar.
The formula for determining the exact change is:
P∆ based on T∆: psi2 = ((F2+460)*((psi1+14.7)/(F1+460)))-14.7
Meters to Feet to Meters
Metric-Imperial: 3.3 *meters= feet
Likewise
Imperial–Metric: feet/3.3 = meters
Your adventure awaits.
Becoming a SCUBA diver is a fairly simple process. Honestly, the most difficult things you’ll face are where you want to train (cooler, green waters of the PNW – or – crystal clear, warm, blue waters of the tropics), and what color fins and mask you’ll want. After all, diving is, if nothing else, a recreation of fashion!
The first thing you should do is decide when you want to become a diver. Just like the image below says, no one ever wishes they had waited until later in life!
If you click the image above you’ll open a window that will tell you everything you need and we do different where it comes to this initial certification. Once you’ve decided you’re ready, the next important decision is here, or there. Cold water, or warm. They’re both amazing, relaxing, with a plethora of life to experience, but your affinity for one climate or another will make or break your experience: pick the option that suits you best!
That’s really it. Once you sign we will personally guide you through the rest. No large groups or crowds to get lost in: it’s you and your instructional team from start to finish. The only time that may change is during certification dives. All of your training is designed to focus on you alone, or you and your small group!
Better to have and not need than need and not have.
DAN will CYA!
DAN* dive accident insurance offers divers an affordable way to protect themselves against unpredictable expenses associated with diving accidents and dive travel. Plans pay 100% of eligible accident medical expenses up to US $500,000, and some cover nondiving and named water sports accidents as well as diving accidents, up to and even including recompression therapy and search and rescue.
*Spartan Scuba receives no benefit from DAN, nor do we imply any affiliation other than using and recommending their services.
Let the GI Bill bring your adventure to life!
Did you know that your GI Bill can help pay for some, if not all of your SCUBA dreams to become a reality? It’s true!
Everything from the basic diver all the way up to the top tier of the professional ladder, there is an approved training program which will satisfy your needs.
Get certified to be a Nitrox diver right out of the gate, or how about becoming a Rescue Diver, complete will all the first aid courses?
Ever thought about being a Divemaster? We’ve got you covered.
Wanna’ be a tech diver? Come along with Doc on a deep deco dive, switching between multiple gasses on your way out, and let the GI Bill help you get there.
All of this and more is possible. For more information, click here!
