Ash has basically got you covered, but yes you are lacking an Ice move which is vital for hitting Dragons super-effectively. Just remember that Azumarill has horrible Special Attack so Surf may not be that great other than being able to get around Iris' Aggron's high Defense. If yours has Huge Power definitely give it Ice Punch by trading in some Red Shards to the Move Tutor in Driftveil City.
Otherwise, replace it with a Starmie since you don't have any Special-based attackers on your team. If you do decide to go with Starmie, a good moveset should be Surf, Psychic, Thunderbolt and Ice Beam.
And as Ash said, having too many STAB moves on one Pokemon can render you at a disadvantage like with your Emboar there. You should also go to the Pokemon World Tournament and trade in a Heart Scale to learn Hammer Arm since your Emboar is lacking a Fighting STAB, and most of Iris' team has a bit of a Fighting weakness. In fact, 3 of her Pokemon are weak to Fighting.
Just remember that Iris' Haxorus carries Earthquake, which half your team are weak to.