Repetitive Dives as 40 feet?

[GTDaveMac]

Looking at the YMCA tables, Table C for RNT times says "For repetitive dives less than 40 feet, use the values for 40 feet."

This makes sense, because the table doesn't list times lower than 40 feet.

However, when determining the Total Bottom Time for the next dive in Table A, must you still use the 40 foot line for a shallower dive, say to 20 feet?

{EDIT} I have now found information which states that repetitive dives of less than 40 feet should be treated as 40 foot dives. Also, by referencing the PADI tables and using common sense, the repetitive dives would have to be treated as 40 foot for the RNT numbers to mean anything. So... unless someone has any input, I have answered my question.

 

[Dr Deco]

Hello DaveMac:

What you have found is a concession that must be made when a printed table is made. It is definitely possible to have a table that would function almost like a computer. It would be, however, so unwieldy. For simple dives, it would require pages of tables and require switching from sheet to sheet. Errors would definitely be possible.

For simplicity, depths and times are rounded out and dives below 40 feet are treated as if they were to 40 fsw. This can produce a reduced bottom time, but it will be a simple table that can be printed on a small card. :umnik:

Dr Deco :doctor:

Readers, please note the next class in Decompression Physiology is September 10 – 11, 2005 :1book:
http://wrigley.usc.edu/hyperbaric/advdeco.htm