So your students round a 100ft dive up to 90ft apparently. Which would not be "seamlessly integrating" into whatever "team" you think they belong in this week.
Has nothing to do with cool and everything to do with relevant. You're the one who brought up irrelevant EAD precision calculated to the 1/100th of a foot. As if knowing or not knowing that factoid was somehow important to a budding technical diver's understanding of EAD. Do you force students to round their 21.2/34.8 trimix down to 21.0/34.0 for END calculations to the 1/100th of a foot and up to 22.0/xx for CNS, and fractions of pulmonary units? What on earth for? To prove they "get" it?
News flash, its not relevant on paper or in the water.
The point of my post was that dive planning worksheets can be educational and while I abandoned their use in classes, I feel that I need to bring them back because even well-trained divers such as those coming from GUE seem to lack the ability to correctly use tables and calculate formulas when planning dives.
With the exception of one guy, every student that I've had with a GUE background finds himself or herself scoring poorly on exam questions when it comes to using tables or calculating formulas because they will employ battlefield math. On the fly calculations are great and do work well, but the students forget or don't understand certain rules that are fairly standard procedures across the board from agency to agency.
An example of which is a question on the PSAI advanced nitrox exam which firsts ask the student, "What is the EAD of Nitrox 32 at 100 feet?" The multiple choice answers are: 70 feet, 80 feet, 81 feet, and 92 feet.
With the exception of one guy, every GUE student I've had in class has answered incorrectly choosing 80 feet. All have admitted that they chose to use the battlefield calculation of a 20% reduction in depth when using Nitrox 32 to arrive at their answer. Right away, having been through as many tests as most of you in high school and college, that 80 feet vs. 81 feet looks pretty suspicious to me. That alone might warrant attention to double check my brain by working the EAD formula rather than just doing a "quick calc" on the fly.
The Equivalent Air Depth formula is: EAD = [FN2*(Depth + 33)/.79] - 33
Tables don't calculate to a 100th of a foot, but calculators do.
Using a calculator for Nitrox 32 at 100 feet the values would be: [(.68*133)/.79] - 33 = [(90.44/.79] - 33 or 114.48 - 33 = 81.48 feet. I left the decimals in place in my post so that readers could round up or round down as they chose.
On paper, I'd calculate it as 81 feet.
Call it 81, 81.4, 81.48, 81.5 or 82 feet. Any way you slice it, the student will discover that he or she must now consider that 81 feet is past 80 feet for decompression purposes and must move to the next greater tabled depth of 90 feet.
News flash: That is relevant to the correct use of any dive table and relevant to the correct way to use equivalent air depth and tables such as the US Navy Standard Air Decompression Tables for nitrox diving.
With that knowledge a student can seamlessly integrate with any divers trained by instructors from PDIC, TDI, PSAI, NACD, NSS-CDS, or any other group that uses US Navy, Bulhmann, DCIEM, or any table that instructs the user to go to the next greater tabled depth or time if a tabled depth or time has been exceeded.
