1- Smartphone with predownloaded application.
2-WiFi navigation system connector
3-Base unit of the navigation system
4-Diver's indicator
Smartphone. The downloaded application, via WiFi  bridge is connected to the navigation system. Schematically displays the position of the diver (distance, bearing), and also draws the traversed path.
WiFi module. Using the WiFi module, data of the diver's position  is transferr to a smartphone or tablet.
The base unit. It is installed on the carrier vessel to determine the position of the diver.
Model of the indicator for a diver. Used by the diver, to determine his location. The screen schematically shows the position of the diver, relative to the base unit, placed on the carrier vehicle.