Southwest Maine Day Trip Suggestions?

Girlfriend and I are going to York Beach, ME for a few days this weekend and we want to bring our kayaks and go for a half- or full-day flatwater trip somewhere in the York to Portland area. Any suggestions on an easy access, leisurely paddle?

York Harbor
Scarborough Marsh, Biddeford, Biddeford Pool…

I am about 100 miles away near the Saco River…watch the tides at all those locations. Some mean currents can happen.