Remember the time when users could ride horses under the sea? That was dope!
And also sort of helps to include the idea that Aang/Katara rode Appa underwater and Korra took Naga underwater!
So why not allow the users to either left click as an alternative method?
Well as I agree you should be able to ride things underwater, it does take a concentration to maintain the bubble. I've seen you several times say that a shift represents the concentration of the bender, we need something to resemble their concentration on keeping the bubble in place. However, there is no way to resemble both their concentration AND be able to ride things underwater. When we saw benders use this move in the show, they were never able to execute tasks while they bended the bubble. For instance, Katara at Serpents Pass (I think that's the places name). She had to concentrate on the bubble the entire time and I believe once her mind was distracted, the bubble was destroyed and Toph had to shoot everyone up (I feel like I could be completely making this up, I haven't seen that episode since like 2009-2010 lol). I guess we have to choose what we want more: To show the realistic style of the bending, or to have a more useful version of it. Both I wouldn't mind having.
The Bubble Size should be determined by the oxygen quantity.
This is very interesting to me..... Perhaps we could see water being pushed in other places to fill this "void" area? Notice, if you fill up space in one side of a bowl of water, the water fills the other side. So if you click/shift/whatever to activate the bubble, we should also see the water being "pushed" in the opposite direction of the user to show the water taking up space and to be correct according to laws of physics. Mass cannot be created nor destroyed! Although, not sure how this would turn out in Minecraft....
I think the bubble radius should be set based of how many air and transparent are near the user.
Personally I feel the bubble size should be lessened period. Also, it should get smaller as you progress deeper into the "ocean" or whatever body of water you're in. Pressure underwater increases depending on how deep you are. So as a waterbender, the bubble would be harder and hard to keep up the deeper you go correct?
Like how Korra has done, this passive , only applied to this ability, would provide you and your allies that status effect in a very small radius.
This is to resemble a really small bubble or? I don't recall in the show waterbenders being able to breathe water, much less grant other people the power to breath water.... I'm confused on this part.