Description: This data contains 125 geolocated water stable isotope, salinity, and temperature measurements from niskin bottle samples at varying depths from 52 Conductivity, Temperature, Depth (CTD) casts along the RV Oden cruise track. The CTD rosette water sampling was conducted following the CLIVAR/GO-SHIP protocol with a 'water cop' keeping track of the sampling order. Sampling for gases goes first, followed by nutrients, water stable isotopes, and then microbiological and DNA sampling during each cast. Samples for water stable isotopes analyses were collected by filling 30-mL Nalgene bottles to the brim. Bottles were closed tightly, sealed with parafilm, and stored in a labeled sample bag. Sampling depths chosen were based on the profile, location, and whether samples were collected for nutrients. Two samples were collected per depth. A total of 250 samples were collected from the 52 CTD casts from 19 July – 04 August 2019. The corresponding salinity and temperature measurements per sampling depth were collected from the CTD data. All water samples were transported to the Atmosphere, Climate, and Ecosystems lab at the University of Illinois at Chicago for processing. The δ¹⁸O and dD were measured using a Picarro l2130-I CRDS water isotope analyzer with a wire mesh inserted in the vaporizer inlet to trap salt from the seawater. Fifteen injections were made for each sample and necessary corrections to address 'memory effect' were employed. Measurements were normalized using the dD and δ¹⁸O values of internal water standards. Data table header includes the event, depth (m) latitude, longitude, sampling date, campaign, sampling method, location, isotope analyzer, salinity and temperature sensor, ¹⁸O values (‰), D values (‰), salinity values (psu), and temperature values (°C).