What is the frequency range from 3 kHz to 30 kHz typically used for?

The frequency range from 3 kHz to 30 kHz is typically associated with low-frequency communications, making it suitable for specific applications like fleet communications. This range allows for long-distance communication over the horizon, which is essential for coordinating operations among naval fleets. These low frequencies can penetrate water and are used for communication with submarines, making it effective in maritime environments where line-of-sight is not feasible.

In contrast, other applications such as AM radio broadcasts operate at different frequency ranges, typically between 530 kHz and 1700 kHz, focusing on broader public broadcasts rather than specialized communications. Navigation systems commonly use higher frequencies, such as VHF (very high frequency) and UHF (ultra-high frequency), to provide accurate positioning and navigation information. Submarine communication also typically leverages this low-frequency range, but specifically for communication directly with submarines rather than the broader concept of fleet communication, which encompasses all naval operations and coordination.