The value of coastal and ocean observing is well documented. In particular, both the NOAA-led Integrated Ocean Observing System (IOOS) and the NSF-funded Ocean Observatories Initiative (OOI) have been established to address the management, safety, and scientific needs of the US and to better understand and predict changes to important ocean and coastal resources and processes. A foundation for successful ocean observing is access to, and implementation of, effective, reliable, and standardized sensors and sensor platforms to collect environmental data. The Alliance for Coastal Technologies (ACT) was therefore established by NOAA as partnership of research institutions, state and regional resource managers, and private sector companies interested in developing and applying sensors and sensor platforms for monitoring and studying aquatic systems. ACT goals include: transitioning emerging technologies to operational use rapidly and effectively; maintaining a dialogue among technology users, developers, and providers; identifying technology needs and novel technologies; documenting technology performance and potential; and providing IOOS with information required for the deployment of reliable and cost-effective networks. These goals are accomplished by providing three basic services: (1) a third-party tested for evaluating existing and developing sensor and sensor platform technologies, (2) a comprehensive data and information clearinghouse on environmental technologies, and (3) a forum for consensus and capacity building through a series of annual workshops on specific technology topics. This paper, and associate presentation, will review the ACT program, highlight accomplishments, and discuss trends found during the evaluations of in situ sensors.