Recent research conducted on adults in the United States indicates low ocean literacy (Ocean Project, 2009b, 1999), but there is a dearth of peer-reviewed research on K-12 students' ocean literacy. This paper presents two research studies that examined the ocean and environmental literacy of 464 K-12 students in five states. Like the majority of American adults, most of the student participants in these studies had low initial levels of ocean literacy. Both of these studies, while conducted with different populations of students, suggest that engagement in an ocean literacy-focused program may lead to higher ocean literacy and increased responsible environmental behaviors that help the ocean. The encouraging results of these studies, and their implications, are discussed in relation to the ocean literacy and environmental education communities and the critical need for further large scale and longitudinal empirical studies to support increased significance of ocean literacy in the United States.