Weather in maritime coastal areas is often localized, dynamic, and difficult to predict. The Red Sky mobile application provides a capability to accurately crowd-source maritime weather conditions in real time using a simple, fun, and intuitive interface. These data help mariners conduct safe boating operations and let weather forecasters evaluate and improve the accuracy of their models. Red Sky was developed by Metron, Inc. under a grant from NOAA. The app is compatible with both iOS and Android devices. Red Sky capitalizes on the new wave of Citizen Science initiatives adopted by NOAA and other government agencies, enlisting the general public to make observations using ubiquitous mobile devices. Red Sky collects data from sensors within mobile phones and tablets and from external Bluetooth-connected weather sensors to populate fields in an observation report. Users can see all real-time reports displayed on a map, filter those reports, and set alerts for extreme conditions. Reports can also be sent out over Twitter for sharing in that community.