I've never lived there, so you might want to do more research, but I LOVED cape cod. (Massatusets, oh please don't make me spell that... ) I was in Cape Cod and Marthas Vineyard. All AMAZINGLY dog-friendly. I was really surprised and pleased.

Lots of dog stores, lots of dogs everywhere, a huge thing there is "The Black Dog" which I see suits you also . There is also lots of water, especially around Marthas Vineyard, as it's an island.

The biggie for me was how dog-friendly everyone was. I'd vote it the most dog-friendly place in the states. I loved it there, *sigh* I only wish I'd been there longer.