During a dive, your dive computer provides information that a dive table cannot. In this section, you’ll learn how to read key items on the display while you’re underwater.

■ No-decompression limit (NDL)

Your computer continuously displays your no-decompression limit (NDL). The NDL is the maximum time you can remain at your current depth and still ascend directly to the surface at a normal rate, without making mandatory decompression stops.

As you ascend to a shallower depth, your NDL typically increases because nitrogen uptake slows. For example, even if the computer shows an NDL of 10 minutes at 20 m, that value will become longer as you rise to shallower depths.