All dives are planned as no-decompression dives. Should you stay down longer than planned, for example, if something delays your ascent and you exceed the NDL, you need to make a decompression stop to give your body time to eliminate excess nitrogen. Otherwise, you may be susceptible to decompression sickness (DCS). After exiting the water, do not dive for 24 hours.
If you exceed the PDC's NDLs, the PDC will go into decompression mode, which will give you information about your decompression stop(s): at what depth and how long to stop for. Do not ignore these required decompression stops because doing so could lead to serious problems. Make sure you read and fully understand the manufacturer’s instructions on the use and functions of your PDC before diving.