Hi Geoff,
Good to see indie subsim projects! I would give your project a try but I don't have a Windows install at the moment.
As someone who has toyed with getting the NOAA bathy data into a 3D engine, I'm wondering how you keep your download size so low? The higher res data set (ETOPO 1) is something like 200-300 MB in size.
While I would consider myself a more than competent programmer, I've never done any game programming. So maybe there's just some widely known asset voodoo that I don't know about.
PD