Dive Terms

The NAUI terms - different than what I learned in NASDS

Note for computer users record only:

• SIT,
• Depth,
• Safety Stop
• ADT

Acronyms:

1. (A)MDT - (Adjusted) Maximum Dive Time
2. ADT - Actual Dive Time
3. D - Depth
4. PD/PD+ - Precautionary Depth stop/+ means deep stop. I.e. rule of halves 1.5-3 minutes at half max depth.
5. RNT - Residual Nitrogen Time.
6. SAC - Surface Air Consumption
7. SIT - Surface Interval Time
8. TNT - Total Nitrogen Time
9. DCS - Decompression sickness (Bends)

Nitrox Related Terms

1. EAD - Equivalent Air Depth
2. MOD - Maximum operating depth solves equation 1 below for Depth, Best Mix would give a depth and solve for $$O_{2}\%$$.
3. ATA - Atmospheres absolute (think French) 1 bar = .986923 atm OR 1 bar=1 atm, and 10 M = 1 ATM. ATA = Depth / 33 + 1.

4. CNS - Central Nervous system oxygen toxicity. Plan $$PP_{O_{2}}\le 1.4$$, and never let $$PP_{O_{2}} > 1.6$$

5. PT - Pulmonary Toxicity is not a concern for recreational divers.
6. ConVENTID - Convulsions, Visual, Ears, Nausea, Twitching, Tingling, Dizziness, Dyspenea

Formulas:

1. $$Partial~Pressure = O_{2}\% \cdot Depth_{ATA}$$
2. Henry's Lay states: $$Residual~Nitrogen \sim depth$$ That is, the level of in-gassing you will incur is directly proportional to your depth.