Friendly for All Cressi's new Archimede 2 computer is sophisticated enough for seasoned divers who want to use multiple gas mixes, yet its simple interface makes it a realistic choice for first-time computer divers. It's programmable for two nitrox mixes and features a gauge mode, a PC interface and a profile mode that lets you analyze your dive even if your PC isn't available. There've been hardware upgrades, too, such as making the upper shell user-replaceable (choose from three accent colors) and improving the wrist strap. But what's really exciting is that the Archimede 2 has a new Bühlmann ZH-L8 algorithm with 12 tissue compartments (instead of nine on the previous version) for greater precision in tracking your deco status. With a new computer, I like to start pushing buttons and deciphering features before even looking at the manual. With the Archimede 2, I was able to program both nitrox mixes, set PO2 levels for each mix and then run a simulated dive, complete with depth alarms, ascent rate alarms and nitrogen loading graphs. After this little exercise, I thumbed the mode button a few more times and found it easy to set the computer's time and date functions. Incidentally, I really like that the Archimede 2 allows a good range of PO2 settings, from 1.0 to 1.6 bar. Before hitting the water, I did give the manual a thorough going-over and verified that the settings I'd programmed in were correct. I also learned that switching between gases during a dive is as easy as a five-second hold on one of the input buttons. I discovered that the ascent rate is variable and that the new algorithm penalizes divers less for ascent-rate violations than the previous model (thank you!). A user-programmable safety factor is also available, allowing for three levels of conservatism. Once in the water, the Archimede 2's display is easy on the eyes. Current depth and the no-decompression limit are at the center of the display and are the largest readings. Maximum depth and dive time are also visible, as are bar graphs for nitrogen loading, oxygen exposure and ascent rate. At 15 feet, the computer automatically offers a three-minute safety stop countdown. Violate any of the set parameters and an audible beep is paired with a flashing display to get your attention. The backlight is also activated, and it's bright even in daylight. Overall, I like that the Archimede 2 is sophisticated enough to support a deco mix and allow for some customization, but it doesn't require extensive familiarization before use. And, I'd be comfortable diving this little gem anywhere. The display is intuitive and uncluttered and the optional gauge mode makes it a nice companion for free diving. Cressi-sub Archimede 2 Air/Nitrox Computer Impressions A great upgrade in the Cressi-Sub line. A new algorithm and expanded capabilities are packaged in a system that even a neophyte will love. Features Supports two nitrox mixes (mix 1, to 50%; mix 2, to 99%) and has three conservatism levels, a simulator mode, a gauge mode and a PC interface. User-replaceable batteries are easy to find and will last up to 100 dives.