2010 California Current Ecosystem (CCE) Survey (MILLER FREEMAN). Four frequency (18, 38, 120, and 200 kHz) split-beam, echosounder data were collected from Miller Freeman during the entire spring 2010 CCE survey. The survey transects from legs 1 and 2 totaled approximately 3109 n.mi., including 10 cross-shelf transects and 7 north-south connecting segments, spanning an area from San Diego (ca. 32 °N latitude) to San Francisco (ca. 38 °N), California, and from approximately 5 to 250 n.mi. offshore. The transects were approximately 200 to 280 n.mi. long and were typically 40 n.mi. apart. Leg 1 of the survey commenced with a calibration of the echosounders with the ship at dock in San Diego. After calibration was complete, the ship departed San Diego on 2 April at 18:00 PST (3 April, 02:00 GMT), sailed to the first sampling station (94.9-29.9), and then proceeded westward on CalCOFI Line 95. The echosounders were operated continuously along four transects (Line 95, 91.7, 88.3, and 85), after which the ship pulled into and docked at Port Hueneme, CA on 9 April for personnel transfers. The ship departed Port Hueneme for leg 2 at 17:00 GMT on 12 April. After a one-day weather delay, Miller Freeman sailed northward to Station 81.7-45, and began Transect 5 of the survey. Leg 2 followed Lines 81.7, 78.3, 75.8, 73.3, and 66.7 (traversed in both directions). The vessel returned to San Diego on 22 April.

Prior to the CalCOFI survey (leg 3 of the CCE cruise), the echosounders were calibrated with the ship docked in San Diego. Results and settings from the calibration are described in detail in section 2.3.1. Leg 3 of the CCE cruise departed from the 10th Avenue terminal in San Diego on 26 April at approximately 23:00 GMT, with the planned route (lines 93.3, 90, 86.7, 83.3, 80, and 76.7). Due to bad weather, stations 70 and 60 on line 90 had to be skipped during that transect. Additionally, due to a faulty fire alarm panel, the Miller Freeman had to dock at Port Hueneme on 7 May until repairs could be completed, leading to missed stations on line 83.3. On 13 May, the Miller Freeman left Port Hueneme and continued on line 83.3, with a new cruise plan in order to survey each station. Leg 3 was comprised of 6 cross-shelf transects with 5 north-sound segments connecting each line. The surveyed area totaled approximately 2,120 n.mi. and ranged from roughly San Diego (ca. 32 °N latitude) to Avila Beach (ca. 35 °N).