I'm gonna save you the wait, I'm not doing this. I'm happy with the icons as they are and I don't think following your advice would make them look better. I truly don't understand how you're 'confused' by crossed blades (of the shape that Naga Sirens use) symbolising hold position. The hero skill one I'll give you but I couldn't find an organic underwater way to do the usual equilateral cross, and this was more interesting. For move, 'I get that it's a fin moving but -' ok so you do understand it from seeing it.
You say the cancel one could look more like water, but in the other watery ones there's too much blur and there shouldn't be a coloured background for patrol? A glow around the koi would break the style of the icons being realistically underwater.
I actually used the blur so they would match command buttons, like the move fin resembling an arrow rather than a defined fish tail. I didn't want the eye to get too distracted by crisp details and instead focus on the shape.
Along with pretty much everything I make, this is for a personal project and I share it here so others can use it and it's not just kept to myself. If you think they should be different, you're welcome to edit them yourself.