## 7 Conclusions  
The UOWC technology has generated significant interest among academics and industry as a viable solution to meet the growing demands for high-speed underwater data transmission. This study highlighted the challenges of light propagation in underwater environments and the essential components of the UOWC system based on defining a reliable solution for RTE. Designing an optimum UOWC system relies on determining the main characteristics of the Tx-transmitted optical signal \(h_{p}(t)\) propagating through the seawater channel \(h_{c}(t)\), link configuration, the mathematical algorithm that describes the photons' travelling steps through the channel, and the Rx setting. It is expected that this algorithm expresses the temporal and spatial profile of the received photons \(h_{opt}(. )\) (in Equations (73)-(78)), in terms of the \(h_{p}(. )\) (in Equations (58)-(61)) and the influencing seawater channel's events/impairments (EPES in Equation (62)). In other words, the algorithm reflects the underlying convolution interactions of the optical beam radiance with the channel's IOP, which encompasses the defined EPES. Such a set of algorithms (Equations (73)-(78)) is the backbone of the MCS software solution, which is conceptually a statical formulation based on the CLT. Hence, an efficient MCS programme output should have low variance and reasonable convergence rates. In summary, this communication provided a two-component tutorial report, one for deriving the underlying MCS mathematical equations and the other for the computational programming steps. Furthermore, this survey examined the main optical properties of water, which are classified as IOP and AOP, supported by Tables 3 and 6 and a family of curves in dia \begin{table}
\begin{tabular}{p{11.4 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline  & & **Challenges** & **Future Directions** & **Ref.** \\ \hline
8. & **Modality Switching:** Switching between optical, acoustic, and RF modes to achieve reliable communication is technically challenging. & \(\bullet\) & Develop algorithms for intelligent mode selection based on environmental conditions. & \(\bullet\) \\
8. & **Cross-medium Interference:** Integrating multiple modalities may lead to interference and compatibility issues. & \(\bullet\) & Create systems capable of seamless communication handover between modalities. & \(\bullet\) \\ \hline
9. & **Limited Power Supply:** Underwater systems rely on batteries, which are challenging to recharge or replace. & \(\bullet\) & Explore energy-harvesting methods such as tidal, solar, or thermoelectric cues to power UOWC devices. & \(\bullet\) \\
9. & **Energy Harvesting and Sustainability** & **Environmental Impact:** Ensuring that UOWC systems do not harm marine ecosystems. & \(\bullet\) & Design eco-friendly materials and systems that minimise environmental disruption. & \(\bullet\) \\ \hline
10. & **Advanced Modulation and Coding Techniques** & \(\bullet\) & **Channel Impairments:** Conventional modulation schemes struggle in high-scattering and turbulent environments. & \(\bullet\) & Investigate new modulation techniques, such as orbital angular momentum multiplexing or spatial modulation. & \(\bullet\) \\
11. & **Advanced Modulation and Coding Techniques** & \(\bullet\) & **High BER:** High BERs due to underwater channel conditions reduce communication reliability. & \(\bullet\) & Develop advanced error-correction codes tailored for underwater optical channels. & \(\bullet\) \\ \hline
11. & **Cost-Effective Solutions** & \(\bullet\) & **High Implementation Costs:** Optical devices and deployment infrastructure are often expensive. & \(\bullet\) & Focus on low-cost, off-the-shelf components for UOWC systems. & \(\bullet\) \\
11. & **Cost-Effective Solutions** & \(\bullet\) & **Maintenance Challenges:** Underwater devices are challenging to maintain and repair. & \(\bullet\) & Develop modular, easily deployable systems for quick replacement and maintenance. & \(\bullet\) \\ \hline \hline \end{tabular}
\end{table}