Research was conducted aboard the RVIB Nathaniel B Palmer during NBP14-02 (29 January to 16 March 2014) across a >3000 km2 area. A ‘yoyo’ camera, with downward facing digital still and video cameras mounted within a tubular steel frame, was deployed on a co-axial cable to image the sea floor; still images are presented here. The Ocean Imaging Systems DSC 10000 digital still camera (10.2 megapixel, 20mm, Nikon D-80 camera) was contained within titanium housing. Camera settings were: F-8, focus 1.9m, ASA-400. An Ocean Imaging Systems 3831 Strobe (200 W-S) was positioned 1m from the camera at an angle of 26° from vertical. A Model 494 bottom contact switch triggered the camera and strobe at 2.5m above the sea floor, imaging ~ 4.8m2 of sea floor. Parallel laser beams (10 cm separation) provided a reference scale for the images. During normal deployments, the live video feed was used to determine bottom contact, with the flash of the strobe light indicating the collection of an image. This mode allowed regular spacing between images of 10–20m across the sea floor. Due to technical problems the final four deployments did not include a live video feed, relying instead on a contact alarm which sounded as soon as the bottom contact was activated on the sea floor. Occasional dragging of the bottom contact switch along the sea floor meant that the number of images collected and their spacing was not always known until the images were downloaded.

During normal deployments of the Yoyo camera during NBP1402, the live video feed was used to determine bottom contact, with the flash of the strobe light indicating the collection of an image. This mode allowed regular spacing between images of 10–20m across the sea floor. Due to technical problems the final four deployments did not include a live video feed, relying instead on a contact alarm which sounded as soon as the bottom contact was activated on the sea floor.