A series of observations of the sea breeze has been made along a portion of the New England coast near Block Island, Rhode Island. These observations are presented in vertical cross-sections approximately 30 mi long perpendicular to the coast, with wind observations extending upward to an altitude of six thousand feet and temperature observations up to twenty-five hundred feet. The analysis is confined to two days on which the sea breeze was most clearly distinguishable from the over-riding flow and shows the development of the cellular structure of the sea breeze. The expected rotation of the system under the influence of the Coriolis effect is not at first evident, but an analysis of the behavior of the over-riding gradient flow reveals the possible presence of this acceleration of the wind field. In addition, there is evidence toward evening of a speeding up of the flow at low levels which presages the development of a low-level jet in the wind field. Abstract A series of observations of the sea breeze has been made along a portion of the New England coast near Block Island, Rhode Island. These observations are presented in vertical cross-sections approximately 30 mi long perpendicular to the coast, with wind observations extending upward to an altitude of six thousand feet and temperature observations up to twenty-five hundred feet. The analysis is confined to two days on which the sea breeze was most clearly distinguishable from the over-riding flow and shows the development of the cellular structure of the sea breeze. The expected rotation of the system under the influence of the Coriolis effect is not at first evident, but an analysis of the behavior of the over-riding gradient flow reveals the possible presence of this acceleration of the wind field. In addition, there is evidence toward evening of a speeding up of the flow at low levels which presages the development of a low-level jet in the wind field.