Diver communication, is abit lacking.
Based on game logic, I know its 2035 and all divers are equipped with some kind of radio devices, but I am sure Diving handsignals won't be a thing of the past.
Handsignals such as : "go down", "go up", "are you ok?" are commonly used underwater, and getting those in-game will be a nice feature.
Some of the basic handsignals are shown here: http://www.youtube.com/watch?v=3BHG7gM7I9g
*Might be too late to include the following in-game*
In addition, the way divers actually get in or jump into water should be improved.
For example- Watch these guys roll backwards off the boat ( http://www.youtube.com/watch?v=zUsSRv0SWmA ), and this guy doing the "giant stride entry" (http://www.youtube.com/watch?v=o3XPmfJ-vFQ )