The oceanographic data included in this dataset were collected by the NOAA Pacific Islands Fisheries Science Center (PIFSC), Ecosystem Sciences Division (ESD; formerly the Coral Reef Ecosystem Division) from November 3-18, 2015 with funding from the NOAA Coral Reef Conservation Program. The purpose of the two-week research cruise was to evaluate the impacts of the 2015 mass coral bleaching event in the Main Hawaiian Islands. A modified version of ESD's towed-diver method was used to conduct surveys around south Oahu, west Maui, Lanai, and west Hawaii island. The modified towed-diver method involved towing a pair of SCUBA divers behind a small boat for 50 minutes and covering a linear distance of ~2 kilometers per survey. Each diver was equipped with a towboard and attempted to maintain position ~1 meter above the surface of the reef for the duration of the survey. The oceanographic data was collected with a Seabird Electronics 19P CTD mounted to one of the towboards with two auxillary sensors connected to it, including a Seabird Electronics SBE43 oxygen sensor and a Wet labs FLNTURTD fluorometer and scattering meter. The data were collected continuously throughout each survey and included conductivity, temperature, depth, dissolved oxygen, fluorescence, and turbidity. A complete towed-diver survey includes ten 5-minute segments, with oceanographic data averaged by 5-minute segment to correspond with the visual observations recorded by the benthic diver. At the conclusion of the mission, approximately 90 kilometers of 15-m wide transects at depths ranging from ~1 m to ~13 m were surveyed.