I second Capt. Mark's vote for Cotuit.
Another somewhat less ideal but good kayaking spot would be upstream of Dowses Beach in Osterville, just east of the Cotuit system. There's a nice salt pond just north of the breachway and there's Centerville River, both of which should have plenty of fis
h in a few weeks. The area is a little more confined than the Cotuit bays (watch out for motorboats), but otherwise great.
-bd