Techniques have been developed for the collection of rain on board ships. Chemical and meteorological analysis of rain events shows that rain can be collected for major ions on board ships in a contamination-free manner by using collectors on the windward side of the ship. The results also support the conclusion of Jickells et al (1901) that rain associated with North American air masses has elevated levels of SO4=*, NO3-, and H+, while rain associated with eastern Atlantic air masses has background values.