###### Abstract  
Several industrial and scientific underwater applications require high-speed wireless connectivity. Acoustic communications have low data rates and high latency, whereas attenuation in seawater severely limits radio frequency communications. Optical wireless communication is a promising solution, with high transmission rates (up to Gb/s) and little attenuation in water at visible wavelengths. This study explores the feasibility of white-LED-based underwater optical wireless communication (UWOC) by considering Red Sea parameters. High salinity is the most prominent attribute of the Red Sea that can affect underwater communication and requires investigation. Considering this, the received signal intensity fluctuation under increasing water salinity was experimentally investigated. In the same experiment, the impact of growing turbidity was tested, as it is the most influential parameter and tends to block the entire LED-based communication system with little increase. The experimental results show that the signals are affected less by salinity and more by turbidity but are found to be sufficiently strong to be used for communication in the Red Sea. Finally, it was concluded that a white LED is capable of sending data at the maximum possible salinity values of 40 g/L. However, the turbidity can significantly limit the transmission distance to less than 60 cm. underwater optical wireless communication (UWOC); light emitting diodes (LEDs); Red Sea; salinity; turbidity; short-range communication +
Footnote †: journal: Applied Sciences  
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Footnote 1: [[https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci)]([https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci))  
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from artificial intelligence (AI) to unmanned vehicles (UVs), to boost efficiency, productivity, and sustainability. Underwater wireless communication (UWC) technology plays a vital role in enabling these technologies. In addition, the strategic and economic importance of the Red Sea requires advanced security technology. The UWC plays a vital role in military applications to conduct underwater surveillance, detect intrusion, and plan attacks, if needed. Another military application is to prevent any rival state from sabotaging the waters by laying a communication system in the water. Furthermore, autonomous submarines capable of sending real-time messages through a UWC are being used to control drug traffickers. Moreover, unmanned underwater vehicles (UUVs) and autonomous underwater vehicles (AUVs) are increasing rapidly. Therefore, the amount of data to be transferred and the associated data rates continue to increase to fulfil the demands of the aforementioned applications [8]. Employing underwater cables or tethers to provide data links is expensive, requires additional maintenance, and its installation is restricted or difficult in many areas. In the current situation, underwater wireless connection is inevitable. Acoustic waves are the most commonly used underwater communication system, with a range of several kilometers. Acoustic communication is characterized by extremely low bandwidth (only 100 bps), with high latency owing to the reflections, and relatively low throughput, owing to the speed of sound. Consequently, real-time communication for dynamically managing underwater vehicles and operations is impractical. Radio communication can provide a higher data rate; however, its high conductivity in seawater restricts it to a shorter distance. Considering the abovementioned factors, underwater optical wireless communication (UWOC) is a possible alternative or complementary solution. UWOC offers many technical advantages, including high data rates and secure connectivity. It also provides economic benefits such as reduced installation and operating expenses. UWOC systems can be classified into two types based on the transmitter light source: laser-based (LDs) and light-emitting-diode-based (LEDs).