## 4 Emergent Configurations in the IIoT
### Limitations of IoT for Maritime Operation Enhancement and Possible Research Directions  
The effective implementation of EC and IoT technologies for the operation and management of maritime activities is encountered by numerous limitations including data management challenges, resource constraints, security and privacy challenges, mobility management, and cost-effective communication systems. Firstly, the sensor-based MUE embedded to marine devices can generate large volumes of data which needs to be processed and stored for accurate maritime decision-making procedures. The generated data during the processes of EC needs to be accurately processed in order to guarantee high system performance, efficiency and scalability. Hence, it is required that certain preprocessing procedures be performed where the collected information can be arranged to form clusters by splitting the collected data into smaller groups for more reliable transmission and data processing actions. The development of clustering evolutionary algorithms for the collection and processing of the transmitted IoT-enhanced data for maritime decision-making processes is still an open research area. Secondly, it is worthy to mention that the sensor nodes deployed for EC activities during oil and gas explorations are usually resource-constrained by energy, memory and processing resources. As such, the optimal allocation of network resources for marine oil and gas explorations is still an open research issue. Additionally, developing traffic engineering techniques and energy-efficient protocols for monitoring the EC procedures in oil and gas explorations is still required for the optimal exchange of data during maritime communications. Furthermore, scalable and dynamic SDN and NFV-based architectures/frameworks can still be developed to further guarantee the efficient management of limited cloud memory in addition to mobility management procedures and optimal use of system energy for seamless operation of maritime activities. Thirdly, another challenge of realizing IoT technologies for the explorations of oil and gas in the marine environment as mentioned earlier is data security and privacy. This is because the integrity, authentication and confidentiality of the MUE collected data during EC-based oil and gas explorations requires to be given priority as the wireless interactions of different devices can result in unwanted third user activities such as network tapping, tampering and forgery since most network components will be left unattended due to self-configurations. As such, developing novel security enhancement techniques that will prevent denial of service (DOS) and distributed DOS challenges in order to achieve oceanic exploration confidentiality and privacy in an attempt to avoid system attacks such as false data and malicious code injection, eavesdropping and interference, spoofing, base station and routing information attacks, malicious scripts and worms attacks likewise unauthorised network access etc, is still an open research problem for the IIoT applications of pelagic communication systems. Finally, a significant challenge of maritime operations is cost-effective communications. Satellite communication technologies are usually deployed for the operation of marine activities [51]. Nonetheless, these technologies are known for their high cost despite their rapid developments. To minimize the high communication cost of satellite systems in addition to achieving high-datarate, reliable and lower latency QoS requirements in maritime IoT-based communication technologies, alternative communication techniques such as EC, SDN, NFV, mobile and cloud computing as well as use of multiple directional coastline-mounted directional antennas can be further deployed and connected together for monitoring and improving the operation of seashore maritime activities.