The effect of coastline geometry on sea breeze circulations is investigated using idealized numerical model calculations with a heated and cooled lower boundary. Particular emphasis is placed on the role of coastline curvature in enhancing or diminishing offshore convergence. The change in this response with respect to latitude is explored, with the focus on latitudes approaching the resonant value of 30 degrees. Circulations driven by an idealized oscillating interior heat source are also considered, and differences with the boundary-heated calculations are discussed.