2. To determine the depth of the mixed surface layer and thermocline structure, 270 m. bathythermograph casts will be made at 30 mile intervals and before and after each oceanographic station except as specified below. 3. For variability studies 270 m. bathythermograph casts will be made. a. at 10 mile intervals between stations 19 and 21, 26 and 28, and 35 and 37; b. at 1 hour intervals on current stations. 4. Surface bucket temperatures and water samples for salinity determination are to be obtained at each bathythermograph observation. 5. Bathythermograph data are to be coded and transmitted as per instructions from the Naval Oceanographic Office, Prediction Division at 0000Z, 0600Z, 1200Z, 1800Z. Radio address: FLE NUM WEA FAC Monterey. 6. Current observations a. Occupy two 12 hour current stations, one in the southern section and the other in the northern section of the observational region. Exact location depends upon weather conditions and is to be determined by the field party chief. Currents are to be measured in the mixed surface layer at 10 m., 25 m. and thence at 25 m. intervals with the deepest measurement in the upper portion of the thermocline, while drifting relative to a parachute drogue set at 1000 m. b. Plastic enclosed drift cards will be released at each oceanographic station and at 30 mile intervals when making bathythermograph casts. B. METEOROLOGICAL 1. Standard marine weather observations are to be made and transmitted at 0000, 0600, 1200, and 1800 GMT. 2. Radiation measurements a. Solar radiation is to be measured and recorded. C. BIOLOGICAL 1. Surface plankton tows