One thing that I didn't like in Halo is that you drowned instantly in water( besides in Halo 1, you could drive vehicles in water) but I hope that in Destiny that you could go underwater and explore reefs and look at fish, that would be very exciting because I love fish and coral so I would be underwater most of the time and explore the water.
I would love to have sharks in the ocean as well so that I could avenge my grandpa who was killed by Tiger Sharks which are know for purposefully killing and eating humans. :-(
As an underwater archaeologist irl, I am hugely in favour of submerged sections (exploring crashed ships, lost cities, hidden caverns) but they would have to be VERY well implemented so I doubt it.
Also, it's not the shark's fault that it kills what it means to kill, it's just well evolved. It would rather have had a seal but if there are only humans about (not to mention that the ocean is ITS habitat) and it's hungry, then bad luck you.
[quote]Tiger Sharks which are know for purposefully killing and eating humans[/quote]
So are humans ;)