If I find disagreement between my PDCs and my tables, the tables will win every time. PDCs have not been in use long enough to satisfy my standards of reliability when it comes to my health and well-being on solely.
Why? Why wouldn't the "most conservative" win? If your tables say 20 minutes and your PDC says 15 minutes, on what basis would you say that 20 minutes is fine?
When your dive computer batteries fail you have lost your electronic brains....
If you want to continue diving during that once in a life time vacation to a far away tropical paradise
You can use the old fashioned dive tables --- If you have a set and know how to use the dive tables
SDM
I think this statement has been sufficiently debunked...
But the big point here... is diving a PDC that's been used within the last 24 hours is a bad idea. Better to use a tissue someone else has already sneezed in than to do that.
Why? Because you'll get a shorter bottom time than you would with an unused computer?
It's not ideal, for sure. But, it doesn't seem nearly as bad as, for example, doing a dive, having your computer die, and then doing a second dive with a new computer.
That is an insightful question. As I said before, I learn by discussion.
Just figured it out. Tables are a bit like taking an axe to cut something that describes your dive. The 'Wheel' is like taking a sharper knife to cut more pieces that better describe your dive. A computer can cut far sharper and faster than either.
It is very much like the Calculus. Calculus gives the value that all attempts converge to.
If you start with a PDC, this insight is lost.
Why is all the insight lost?
If I have students plan a dive to 90', then a dive to 60', then a dive to 50', why is there any less insight available if they plan the dives using the planner on a PDC, or planning software on a PC, than if they planned them all using tables?
What if they planned them all using Subsurface (free software for PC, Mac, etc.), which would show a graphical illustration of tissue loading for each dive, and which reflects the residual nitrogen from dive 1 in the graphical representation that it shows for dive 2, and etc..? How is planning the same dives with tables even remotely as instructive??
I think it's actually pretty cool to plan a series of dives in Subsurface, see the tissue loading in dive 2, then go change the start time of dive 1 and see how that affects the tissue loading shown in dive 2 because of the change in length of the SI. Ditto for simply changing the start time of dive 2 itself, to see how the tissue loading changes as a result of a shorter or longer SI. I think it offers MUCH more insight than plodding through a multi-dive plan with tables.
