What is the significance of a surface interval when planning subsequent dives?

The significance of a surface interval when planning subsequent dives primarily lies in its role in reducing nitrogen build-up in the body. When divers breathe compressed air underwater, their bodies absorb nitrogen due to the increased pressure. As divers ascend and surface, the pressure decreases, and nitrogen begins to leave the body. However, this process takes time, and a surface interval allows for additional nitrogen to be expelled safely from the body, reducing the risk of decompression sickness, commonly known as "the bends."

By incorporating adequate surface intervals into dive planning, divers can ensure their bodies adjust to the nitrogen levels before undertaking further dives, thus promoting safety and health. This practice is crucial especially when multiple dives are conducted during a single day. Properly calculating and respecting the appropriate surface interval is an essential aspect of dive planning that keeps divers safer and helps to manage exposure to nitrogen effectively.