What feature of a dive computer requires wireless communication with the first stage of a regulator?

The feature of a dive computer that requires wireless communication with the first stage of a regulator is gas integration. This capability allows the dive computer to receive real-time data about the diver's tank pressure and remaining air supply directly from the regulator. By integrating this information, the dive computer can calculate and display important data, such as remaining dive time based on the diver's air consumption rate and current depth.

Gas integration enhances the safety and efficiency of dive planning and execution by providing the diver with continuous updates on gas levels, helping to prevent situations like running low on air. This function is particularly valuable in multi-gas diving scenarios, as it can manage and switch between different gas supplies. Other features like depth measurement, navigation, and temperature tracking do not require this type of real-time communication, as they rely on different sensors and do not involve the actual tank pressure data necessary for gas management.