Hi, and welcome!
Looks interesting. But why UE4 and USML? UE4 is very limited for a simulator, the area is limited to 20x20 km (if I'm not mistaken), it is slow, and I just don't like dotnet

, and moreover, you have to link it with C++...
And, in my opinion, USML is too heavy for a game (or perhaps I should say "real-time simulation"

). Also, consider the oceanographic data, I doubt you will find it for every point of every ocean, sea, etc. The whole idea of such perfect precision is questionable without it. I'm not even talking that acoustic equations are not perfect themselves. Add classified data on submarines, sensors, etc. to that.