This part of DS 781 presents fault data for the geologic and geomorphic map of the Offshore of Gaviota map area, California. The vector data file is included in "Faults_OffshoreGaviota.zip," which is accessible from https://doi.org/10.5066/F7TH8JWJ. These data accompany the pamphlet and map sheets of Johnson, S.Y., Dartnell, P., Cochrane, G.R., Hartwell, S.R., Golden, N.E., Kvitek, R.G., and Davenport, C.W. (S.Y. Johnson and S.A. Cochran, eds.), 2018, California State Waters Map Series—Offshore of Gaviota, California: U.S. Geological Survey Open-File Report 2018–1023, pamphlet 41 p., 9 sheets, scale 1:24,000, https://doi.org/10.3133/ofr20181023. The southwest-striking south strand of the Santa Ynez fault obliquely cuts the shelf in the western part of the map area. As mapped onshore by Dibblee (1950, 1988a) this fault is unique among Santa Barbara fold belt structures in that it obliquely crosses the Santa Ynez Mountains and the dominant east-west structural grain. The fault was difficult to map in the offshore, even with our dense seismic-reflection data coverage, because the pre-LGM section on the shelf includes massive "reflection free" zones, probably associated with gas or steep dips, and the adjacent slope is mainly underlain by massive to chaotic seismic facies of the Conception Fan. References Cited: Dibblee, T.W., 1988a, Geologic map of the Solvang and Gaviota quadrangles, Santa Barbara County, California, edited by H.E. Ehrenspeck (1988): Dibblee Geological Foundation, Map DF-16, scale 1:24,000. Dibblee, T.W., Jr., 1950, Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota quadrangles: California Division of Mines and Geology Bulletin 150, 95 p., scale 1:62,500.