What is the primary reason for using a diving computer or dive tables with Nitrox?

The primary reason for using a diving computer or dive tables with Nitrox is to ensure compliance with specific No Decompression Limits (NDLs) for the chosen gas mixture. Nitrox consists of varying percentages of oxygen and nitrogen compared to regular air. Different mixtures allow for different dive profiles, particularly in relation to how long a diver can spend at certain depths without needing to perform mandatory decompression stops on ascent.

By utilizing dive tables or a diving computer, divers can accurately track their NDLs for the specific Nitrox blend they are using, which helps manage their exposure to nitrogen and reduces the risk of decompression sickness. These tools provide crucial information to ensure that divers remain within safe limits, making them essential for responsible diving practices with Nitrox.

The other options do not properly address the purpose of dive tables and computers. For instance, increasing dive time beyond standard limits could lead to safety hazards rather than compliance with safe diving practices. Decreasing the need for dive planning is contrary to good diving practices, as thorough planning is essential for safety. Lastly, while proper use of diving computers and tables certainly reduces risks, they cannot eliminate all risks associated with diving. Adhering to NDLs is a key strategy for managing those risks effectively.