Marshlands ebb and flow just off a 1.3-acre by-the-bay property on the Surf Oaks Marsh side of Pine Gully in Seabrook. Neighbors across the wetlands are pretty quiet — they include rugged Pine Gully Park and Seabrook Cemetery. The porched, patioed, and pavilioned home appeared on the market last week with an asking price of $625,000. Back in 2009, it sold for $400,000 (when the asking price was $449,000).