Many useful ocean engineering systems, such as autonomous oceanographic sampling networks (AOSNs) are actually systems of systems. Such systems are complex and require simulation during design and development. However, adequately simulating such systems is also difficult. We have developed an approach to multi-fidelity simulation that allows systems of systems to be simulated at several points along the spectrum from high-level, low-fidelity to low-level, high-fidelity simulation. We have implemented this approach a simulator for the CoDA (Cooperative Distributed AOSN control) project. Such an approach provides simulation support throughout the lifetime of the project, from design through proof-of-concept and beyond.