Although I use a diving computer (two on technical/decompression dives), I still use tables. Commercially, proprietary tables are used (yes, large commercial companies create their own) and also develop their own computer decompression programs as well. I've planned/used tables for saturation dives, but in the past few years these have been monitored by computer.
For those using the U.S. Navy Tables, remember that these are designed for Navy Divers. If you're not in the same condition as a SEAL, you might consider building in a safety factor when using them. These tables if used within there parameters will cause DCS to occur in approximately 2% of the dives. As you go into decompression this jumps to as much as 5% and extreme exposure can be as high as 10%. So don't think that by following the tables, you're not going to get DCS. It can happens even though your careful.
With some computers, you can optionally select a conservatory factor to use which builds in a fudge factor. DCIEM for example, has "Sport Diving Tables," which are more conservative than some others. Different makes of computers use different algorithms, so this is something to consider before you select one to use. Also your risk of DCS increases if the following considerations are present: gender (women are at higher risk), obesity, fatigue, age, physical condition, exercise after diving and environmental factors (cold water, rough seas, heavy work, dehydration and other factors. Don't push it.
