Hey there

I recommend 'Splash Gordon'.  I dont know the cost but they'll do a good deal.  The pool dives are held at Freyberg Pool and the theory at the shop.  They have a good crew and every weekend there's a shore dive, $35 full gear hire or $10 for tank hire.  It's 432 The Esplande, Island Bay so you can fully gear up at the shop and immediately walk into the ocean for a shore dive, if the weathers right.  Otherwise they'll ferry you somewhere else.

I have heard mixed reviews about Dive HQ in Kilbirnie, but you're welcome to try it out.

Splash also do 'free diving' (snokel & fins) course which I would be keen on.  I'll be going for a shore dive this Saturday! Yo Shawn