Introduction to Dive Tables & Computers

During Chapter 5 you learned that decompression sickness can occur during ascent if your tissues and bloodstream contain too much nitrogen. The amount of nitrogen you ingas during a dive depends on several factors, with depth and dive time having the most significant influence.

Before you dive, it's important to review your dive tables or computer to verify that a planned depth and dive time will allow you to ascend without developing decompression sickness. If the planned dive exceeds the maximum limit, you'll need to reduce your maximum depth or dive time to keep the dive within safe limits. This chapter covers the procedures and rules for using your dive tables and computers to make these calculations.

Note: Specific terms, dive time limits, table features, and general table design vary between certification agencies. For this reason, the information presented by your instructor may differ slightly from what's presented in this chapter. Your instructor will highlight any significant differences during your classroom sessions.

divers planning a dive using a table


There are many dive tables used by divers. Most certification agencies publish their own dive tables, and as a result, dive tables vary in both layout and values. For this reason, DO NOT use the tables in this site when taking quizzes or exams, as not all tables caluculate the same results.

Scuba-Tutor's Dive Tables

In deciding on an appropriate dive table to use on, four criteria were considered. It must be in the public domain, be similar in use to other common tables, be conservative (more restrictive than the majority of tables), and have a layout that's appropriate for online display.

The tables used in this site are modified U.S. Navy dive tables, which are the foundation of most dive tables used in the industry. They are very similar to the tables used by NOAA, NAUI, SSI, and many other agencies. Examples of other tables are:

Other dive tables can be found with a simple web search.