I really can't see Kingler being BL. 130 base attack is pretty damn powerful in UU (and, though he lacks an ice attack to deal with grass types, he does have X-scissor), but Kingler is also fairly slow and fairly easy to kill (on the special side of things, anyways). Quagsire takes 37.56% - 44.16% from an Adamant CB return, Pelipper takes 41.05% - 48.15%, and Gastrodon takes 39.67% - 46.48%, which is pretty strong...but the point bears repeating about it's slow speed and fragility (which also prevent it from being a real solid Swords Dance user, though it's still a threat). I can see him being one of the better UU pokemon and certainly a threat that needs to be accounted for when building a UU team, but not something that completely unbalances UU.
Edit: Oh, wait, Gastrodon is neutral to water. Forget that, then.
Azumarill I did want to bring up, though. I'm not sure if Metalkid's calculator has Huge Power put in correctly, though (Huge Power is supposed to double attack, but on the calc it gives less of a boost than +2 attack). So...eh.