What is the primary purpose of dive tables in planning dives?

The primary purpose of dive tables is to provide no-decompression limits and guidelines for safe ascent. Dive tables are essential tools that help divers understand the relationship between depth and time underwater, specifically regarding the amount of nitrogen that can safely dissolve in the body while diving. They outline the maximum time a diver can spend at a certain depth without needing to perform decompression stops during ascent.

By using dive tables, divers can plan their dives to stay within safe limits, reducing the risk of decompression sickness, commonly known as "the bends." These tables are based on established scientific principles regarding how nitrogen behaves under pressure and how it is absorbed and released by body tissues. Adhering to these limits ensures a safer dive experience, allowing divers to enjoy their time underwater without exceeding physiological safety thresholds.

The other options, while related to diving, do not encapsulate the primary function of dive tables in the context of safe diving practices.