IMO, this is either UP or just unuseful... We need more Flooding mechanisms before any "underwater" mechanic can be successfully implemented.
Right now it:
Works with Flooding (dunno how well), and ONLY with Flooding.
It's UP with any other combos. Buffing it is a Trio, and anyways, not a great deal. If not, it's overshadowed by spark.
I think the community isn't ready to balance this stuff, but that's just my .50