By coincidence, I just finished playing a Water Blaster earlier this week. Mostly solo, only a couple of levels on a farm, and all Tier 4 incarnate powers without a single trial. (Could never find one when I was logged on.) 🙂 It was actually one of the most fun characters I've played. With only one purple set (on the secondary power set) and one ATO set, I had a mini-nuke and Judgement, which let me get through crowds pretty quickly. It made me wonder what I could do with her if I invested more on sets.
That was a blaster, though, NOT a defender. I didn't know water was a secondary for defenders. I suspect the experience would be a lot different.