Agreed on that, should be a fortitude save for anything in the water. This is a nice adaptation of produce flame, and I wouldn't worry about one or two thematically appropriate spells being added to the bard for a specific character concept, but I would be wary about making it specify as a bard spell in the description. Whereas it's fine to allow a player access to a small handful of spells around the theme they wish to play, it's a different matter to create something outside the norm as a general option for anyone of the class.
EDIT:
For those saying this is better than produce flame because of the liquid proviso, I'd say not really. You get a highly situational utility from the spell, true, but you also only get 60ft ranged attack instead of produce flame's 120ft. I'd say that balanced it out nicely anyhow.