UNDERWATER WIRELESS COMMUNICATIONCommunication between two entities can be wired or wireless. The concept of wireless technology was started in 1923. As we all know, 70% of the Earth is completely covered by water. It was necessary to develop a wireless network that could also work underwater. Here arises the notion of acoustic waves. Acoustic waves work best in water. They can also travel long distances in water and are very fast than radio waves. The concept of underwater wireless communication constitutes a major discovery in the field of wireless communications. Applications include discovery of natural resources, marine phenomena, deep sea archaeology, oceanographic data collection, etc. WORKFor the operation of underwater wireless communication, acoustic waves are commonly used, which can travel longer distances. But when designing the acoustic channel, we may face problems such as low speed of sound propagation loss, that is, severe frequency-dependent multipath. These facts make it difficult to design underwater wireless communications. There are several ways to use such communication to send and receive messages underwater. The most common is to use hydrophones. As mentioned, underwater communication is difficult due to factors such as multipath propagation, channel temporal variations, low available bandwidth, and high signal attenuation, especially over long distances. Data rates in underwater communications are low compared to terrestrial communications because underwater communications use acoustic waves instead of electromagnetic waves. The large non-scalar components of the acoustic field...... middle of paper ......] , dynamic source routing [DSR]) are more suitable for dynamic environments but incur higher latency and still require a source-initiated flood of control packets to establish the paths. Reactive protocols may be unsuitable for underwater networks because they also cause high latency in path establishment, which is amplified underwater by the slow propagation of acoustic signals. Geographic routing protocols (e.g., greedyface-greedy [GFG], partial topology awareness forwarding [PTKF]) hold great promise for their scalability functionality and limited signaling requirements. However, global positioning system (GPS) radio receivers do not work properly in the underwater environment. Nevertheless, underwater sensing devices must estimate their current position, regardless of the routing approach chosen, to associate the sampled data with their 3D position.