Data crowdsourcing is a increasingly pervasive and lifestyle-changing technology, due to the flywheel effect that results from the interaction between the internet of things and cloud computing. In smart cities, for example, many initiatives harvest valuable data from citizen sensors. However, this paradigm has not seen significant use in coastal and marine monitoring and management due to the challenges of the marine environment. In this work, we describe how this situation can be overcome via the adoption of an open technology ecosystem that provides leisure vessels with a platform for on-board data acquisition, storage, and processing, leveraging off-the-shelf mobile technologies. We introduce DYNAMO, a infrastructure designed to collect marine environmental data from a distributed sensor network carried by leisure vessels. The resulting crowdsourced data can be used to improve operational weather and marine predictions via the use of data assimilation methods. We show our preliminary results about the DYNAMO Daemon, a SignalK server we embedded in the native level of the Android operating system enabling the data gathering and transfer from vessels to the cloud.