What happens when you dive off the Padi dive chart?

Question

If I dove at 140 feet for 40 min with a decompression at 20 feet 4 hr top time and 2nd dive same depth.

Answer 1

Since you didn't mention how long your deco was nor what gas you used on your deco, let's just assume you didn't make it to the surface in any shape for a second dive. That's also a pretty shallow first deco stop, you may not have even made it there providing you even brought along enough gas to have done that bottom time in the first place. Let's just say you might want to take PADI's DSAT Tec Rec course first.

Answer 2

You need a different set of tables.  The PADI tables are for Recreational, non deco diving.  Past 130 feet, your into technical diving.

Answer 3

Making some assumptions: Diver traveled up at 30'/minute, :40 bottom time starts at reaching deepest depth, travel time and deco stops are counted in bottom time, diver is not using a computer or doing a diving a multi-level dive.

This is a safe dive on the U.S. Navy Air table 9-8 140'/:20 schedule. The actual bottom time is around :18 for the dive you described using the assumptions I made above. The diver comes up with an "I" RGP on the Navy table. After 4 hours he is a "C" with an RNT of :07 for 140'. Then the dive can be repeated and the diver comes up with an RGP of "I" using the 140'/:20 schedule or "J" using the 140'/:25 schedule (see reference below).

This is not how the PADI table works and is outside the training PADI provides. But, as scubabob stated there are other tables and training you can use to make dives like this.

http://www.coralspringsscuba.com/usn/Cha...