Blastoise defender moveset

bite no stab , coverage is not enough
water gun at least got stab no matter who you fight against

Bite doesn't get STAB, unlike Water Gun; so I imagine that is the reason Water Gun with Ice Beam is rated better than Bite with Ice Beam.

Pretty sure water gun/flash cannon best defensive moveset! WIth bite and ice beam next on the list!

That Blastiose is a good dragonite counter. The stab bonus on water gun gets cancelled out cuz of dragons resistance to water so in the end bite does the same damage as water.
I use mine with my Lapras when taking down gyms with multiple dragonites. It works better than a dewdong or cloyster cuz its way tankier and has a higher CP.