I just want to second Christian's comments about the class. It was totally enlightening about the concepts of decompression theory, taught in a simple and elegant way, easy to understand. In its simplest form, Ratio Deco adds a layer of security to a recreational dive that accidently (or on purpose) pushes the NDL limits. It's by no means a stand-alone program on decompression diving, but it provides an amazing base.
Jeff
Jeff