Well, I like my computer. When I learned to dive, computers were in their infancy. We were told they existed, but that's about it. Now, they're almost as commonplace as BC's. The other week, we dove a wreck at 100 FSW. Tables allow for about 20 min dive. With my computer, I almost went into deco on the wreck, then came up and swam along the reef at about 30-40 FSW for another 35 min. Try that using the tables. I guess you could try "The Wheel" from PADI if you REALLY wanted to avoid a computer...