[HoneyBadger]

I play water nations primarily, and I also feel that water nations are somewhat slighted. One of the advantages, though, is that you know you're only competing with Oceania, Atlantis, and R'lyeh for the best territory, maybe Agarthia and Vanheim. That's a big advantage, and water has others, like no underwater archers. You have to be careful with proposing changes to water nations. Their are tons of things that can be done, for instance spearguns for Oceania, but finding a balance isn't easy, and the designers understand that.

In terms of story, it's going to take more magical effort to move, fluidly-no pun intended-a large sphere of water, just because water is so dense and heavy. Now, having the power to move that water, the amulet of the fishes should give the wearer added protection on top of being able to breathe air, such as acting like an air-shield against missles, diluting airborne poisons and acids, protecting from heat and cold, etc. Ofcourse, it would make the wearer more susceptible to lightning. I could see Amulet of the Fishes being construction 6, if it really does create a sphere of water, but I think it just needs a little bit of description-tweaking.

I honestly haven't done much with Oceania, just because I prefer the themes of the other two water nations, as well as the details, but that's just personal preference. It can be made to work, and work well, I have no doubt. As to specific strategies for using them on land, declair war on the amphibians. I know that amber tritons are nasty independents, and independent provinces of such usually give me much more trouble than sea-trolls, unless the sea-trolls are slaves. You should be able to capture, and more importantly, hold, territory in the ocean better than any of the other water nations, and it's those conquered provinces which are going to give you the troops you need to duke it out on land.