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Simulation and experimentation of underwater networks entail many challenges, which for the former are mainly related to the accurate modeling of the channel behavior, while they are typically logistic in nature for the latter. In this article, we present our experience with WOSS and DESERT Underwater, two open source suites address both classes of challenges. The suites build on and extend the capabilities of ns2 and NS-MIRACLE, two widely known software packages for network simulation. WOSS endows NS-MIRACLE with the capability to generate realistic channel patterns by automatically retrieving and processing the environmental boundary conditions that influence such patterns; DESERT Underwater makes it possible to evolve toward at-sea experiments by reusing the same code written for simulations, thereby minimizing the effort required for network deployment and control. Both suites have been widely tested and used in several projects: some examples are provided in this respect, including an account of some experiments carried out in collaboration with the NATO STO Centre for Maritime Research and Experimentation

In this paper, we discuss the performance of different network protocols for RACUN, a European Defence Agency project with the objective of demonstrating ad hoc underwater networks for multiple purposes related to security. The RACUN network is designed for long-range communications over areas of large size, hence a very important role is played by the network protocols employed. We show that the channel realizations observed in typical scenarios and the physical layer schemes available in the project lead to significant bit error rates. Therefore, the protocols that offer some inherent form of redundancy, as in the case of flooding-based protocols, tend to yield better performance than protocols based on the exchange of signaling traffic. In support of this statement, we simulate two scenarios for the RACUN network over channel realizations that are statistically derived from real channel measurements. Our results provide insight on the advantages and drawbacks of the different packet forwarding strategies, and confirm that flooding-based approaches perform better. In addition, we prove how splitting packets into multiple fragments to match the modem's maximum service data unit significantly limits the performance

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