This dataset is one of several collected as part of the Bureau of Ocean Energy Management (BOEM)-funded California Deepwater Investigations and Groundtruthing (Cal DIG I) project. The purpose of the study is to assess shallow geohazards, benthic habitats, and thereby the potential for alternative energy infrastructure (namely floating wind turbines) offshore south-central California due to its proximity to power grid infrastructure associated with the Morro Bay power plant. This dataset was collected as part of a geophysical survey aboard the NOAA Ship Rainier during two legs at sea, the first from 8/28/2018 to 9/7/2018 and the second from 9/10/2018 to 9/21/2018. Multi-channel seismic (MCS) reflection data were collected using a SIG 2-Mille minisparker and a 64-channel streamer, although the majority of the survey was conducted using a 56-channel setup due to technical issues with one 8-channel section early on in the survey. Chirp data were collected using an Edgetech 512i towfish with a 1-6 kHz sweep. Consistently high winds and rough seas prevented additional Chirp data collection and caused noisy data in some cases, especially during the second leg of the survey, which largely took place in the southern part of the study area. MCS data provided here are processed to post-stack time migration and both MCS and Chirp data include filtering and other noise removal corrections. Together, these data provide comprehensive high-resolution imaging of the subsurface in the study area, providing a geophysical basis for shallow geohazard assessment.