O-ring once bubbled...
1) On your BSAC comment - same with CMAS. One of the guys I dive with is from France and he has French deco tables that were given to him in his level 1/basic class.
2) Not really on the custom table thing. A lot of my diving is similar and I can use the tables over and over. For example, most of the dive ops I dive with down in NC bank EANx30 and most of the wrecks are in the 100-120' range. I can cut backup tables for depths between 60-130 feet on EANx30 with a time range from 10 mins to 40 mins and have 99.9% of the potential bailout I would need.
You are given just the most basic information.. decompression diving is not to be taken likely.. hook up with an experienced technical instructor.. following a computer or tables blindly is a disaster waiting to happen.. ANy time you are deco diving you must plan contingencies since there is no option to surface.. you must treat all deco dives as though you were in an overhead enviroment with no direct ascent to the surface.
The more deco dives you run the more you will become familiar with your common profiles.. many of the dives I do I have no need to carry any tables (they are written down anyway, as a precaution) with me since I have done the profiles so many time I know what my stops are supposed to be...
If you are asking these questions you are already admitting you don't have enough training.. A good instructor will explain the different deco theories that are currently being used and explain how different programs differ and why..
I personally like Vplanner, this generates probably the absolute minimum deco required of any program but with it comes many issues.. The profiles must be followed EXACTLY (up to the last stops which can be extended) any deviation from ascent rates causes the profiles to become invalid..
let me pose a few questions to you, and honestly answer if you thought about these..
Do you have a PFO??
Do you carry a backup mask and why??
Do you have a means of a stable deco platform if an ascent line can't be found??
Do you know how much gas you will need to complete your deco before the dive or how much bottom gas you will need??
If you answered I don't know or I never thought about it, to any of these more training is definately in order..
These are just some of the issues that should be covered in a good deco class..