The protected species monitoring program, initiated in response to Onslow Bay, North Carolina, United States being identified as a potential site for the United States Navy’s Undersea Warfare Training Range (USWTR), is now into its third year. To estimate marine mammal density, distribution, and seasonality, a multi-platform approach was implemented using traditional visual line transect survey methods from aerial and vessel platforms along with passive acoustic monitoring from vessels and moored instruments. This project represents a long term data set used to assess residency and abundance patterns of this offshore area in the waters off North Carolina. The original survey data are separated into two datasets, from left and right observers. This dataset is from the right side sightings data. The left side sightings data are available on OBIS-SEAMAP in the USWTR Onslow Bay Aerial Survey -Left side- 2008-2010 dataset.