**6. Conclusions**

In this chapter the chance to use RFID technology for systems operating under water has been analysed.

The composition of salt and fresh water has been described, together with the influence that the salinity has on the conductivity of water and then on key parameters like water attenuation and penetration depth. The value of this second parameter has been calculat‐ ed for the standard RFID systems: the results show that only at Low Frequencies it's possible to develop solutions where a long reading range is required, both for salt and fresh water. Anyway, moving at higher frequencies, while for fresh water the chances to set up efficient solutions are still high, especially for short range applications, for salt water RFID becomes virtually unusable.

However, the chance to use the lower frequency bands has led to the development of some applications that use RFID technology for specific purposes, both in marine and in fresh wa‐ ter environments. These applications range from animal tracking solutions to environmental monitoring systems, and represent a good starting point for a wider diffusion of this tech‐ nology even in a sector traditionally precluded to technologies relying on electromagnetic fields for their functioning.
