There are almost as many approaches to ascending from a dive as there are divers to try them. Most divers follow contemporary guidelines and approximate a 30 feet-per-minute ascent rate, while others may opt for double that rate. Some divers will follow whatever their computer dictates, and still others will ascend just a touch slower than their own bubbles. The result is widespread confusion about where the data for these various approaches comes from, and what constitutes a safe ascent rate. Is there a magic formula that divers can use to ascend at the end of dives to minimize their risk of decompression illness (DCI), and what are the costs of ascending too quickly?