###### Abstract
The use of RF, however, is limited to extremely low-frequency ranges due to severe spectrum attenuation, and this requires large antennas and transmission power, posing challenges for compact UVs [19; 23; 24]. Shallow-water strategies such as propagating the signal over the water-air barrier may reduce attenuation [25], but this might not be suitable for all applications. Magnetic induction (MI) for underwater communication, on the other hand, a novel research area, is based on inducing signals between coils of wire. The technology is relatively new, with a limited transmission range and challenges with the alignment of coils, complicating mobile scenarios [26]. Recent work explores sound-driven triboelectric nanogenerators (TENGs) as an alternative [27]. While promising, TENG's fundamental frequency currently limits data rates, requiring extensive research before high-bandwidth information transmission becomes feasible. In contrast, underwater optical wireless communication (UOWC) employs light frequencies within the visible range of the electromagnetic spectrum (EM), taking advantage of wavelengths that show the least attenuation. Such communication enables the transmission of >1 Gbps over few hundred meters in point-to-point (P2P) configurations. For example, [PERSON] et al. and [PERSON] et al. have showcased data transmission rates of 16.4 Gbps (488 nm, up to 10 m range) and 12.4 Gbps (450 nm, up to 1.7 m range), respectively, using lasers [28; 29]. They have also achieved a 205 Mbps connection over a 10 m distance using blue light-emitting diodes (460 nm LED array with 70 W total output) [30]. UOWC faces challenges such as directionality, where light obstructed by objects like fish or debris may cause signal loss. The inclusion of multipath propagations could address this, but with limitations in shallow water. In shallow water, the length of the alternative signal path may exceed transmission distances, leading to greater attenuation and also absorption of reflected multipaths by the seafloor [19; 24]. In addition to this, environmental conditions such as ambient light, scattering from suspended particles, and refraction with varying refractive indices along the propagation pathway deteriorate signal quality. Nevertheless, these drawbacks may be overcome if the system's adaptability is improved, given that UOWC's potential is underscored by the channel's high capacity, low latency, and low cost per bit compared to other wireless alternatives. For example, off-the-shelf components such as lasers, LEDs, and photodiodes (PD) can be used to build high-frequency emitters and receivers and thus employ modulation and diversity schemesthat enhance bandwidth and range, which is an advantage over acoustic or RF systems that require costly, complex transducers [31]. Furthermore, even though optical link ranges are of moderate length compared to acoustic options, this could be beneficial toward the cellularization of networks with better security advantages and improved sharing of bandwidth, similar to wi-fi, while multihopping could be a sound solution if long distance communication is needed [32]. This way, by adopting strategies like those used in existing terrestrial mobile wireless networks, UOWC networks could be established as both localized and widespread (cooperative) connections between UUVs and other static or mobile devices, as shown in Figure 1.  
The spectra favorable for UOWC span a bandwidth that is within the solar spectrum. Sunlight may therefore affect link quality. In addition to this, UOWC SNR studies often ignore that ocean bodies are inhomogeneous. The effects of sunlight and medium inhomogeneity on transmission wavelengths and beam characteristics are underexplored. Therefore, to address this research gap, we have  
1. Investigated the effect of attenuation on the end-to-end diffused line-of-sight and point-to-point line-of-sight UOWC systems under eight realistic ocean stratification scenarios in order of increasing turbidity, under a \"night condition\". 2.