I tried playing a few missions. It's pretty much the same except the game system is based on MH2. Lack of time and fatigue due to overheating (very hot lah these few days), I didn't get to play it much.

On the side note, maybe this thread should be changed into a general MH thread since the MH3 thread is pretty much dead anyway.

Nope, MHG has no underwater exploration. If you haven't noticed, this topic is mostly discussing about MH3 lol. Not a lot of people cared about MHG because it's a very old game with some new features. To be honest, I bought the MHG starter pack for the Classic Controller (need one for the future) and the MH3 demo. MHG can wait until I'm bored of the demo.