Not that I’m aware of it. There were some issues with fog in 5 IIRC, so maybe that’s the reason why that doesn’t work anymore (I believe they’ve actually fixed fog for Windows Phone but to do that they’ve changed the approach I believe, which of course might break old stuff).
Fog is working above the water surface at least for me, but not under the water surface, even if it’s one mesh, the part above is affected by fog, but unfortunately the part below it isn’t, which is really looking odd, not sure if this is part of bug reporting? Maybe I can report a bug about it?