STUART, Fla. — A rancid smell penetrated the front of Marisa and Duncan Baskin’s one-story house, which rests less than 100 feet from an inlet of the St. Lucie River in this tourist hamlet just inside the Atlantic coastline that bills itself as “America’s Happiest Seaside Town.”

But the Baskins — whose 22-month-old daughter, like Ms. Baskin, suffers from asthma — and their neighbors are not so happy these days. In the water of the inlet of their subdivision in Northriver Shores, an inch-thick layer of bubbling ooze and slime emits a stench so overwhelming that none of the neighbors go outside.

In fact, the Baskins were preparing Friday to stay with friends across town for the weekend just to get away from the green and blue algae bloom that has overtaken their small neighborhood marina, from which most neighbors have moved their boats.

“Our lives revolve around the water; we have a boat, surfboards, and there’s nothing really to do here without the water,” Ms. Baskin, 31, a lifelong resident of Stuart who works as a social worker at a local hospital, said Friday. “And I think our governor and local politicians are to blame. This isn’t the first time this has happened, but it’s definitely the worst.”