Studying sea turtles when they leave coastal areas is a particular challenge for research and conservation. As part of a large-scale fish-monitoring programme, we have deployed mid-water stereo baited remote underwater video systems (BRUVS, Letessier et al. 2013) at 181 sites around northwestern Australia. From 27 turtle observations, we identified 11 green turtles (Chelonia mydas) around Dirk Hartog Island, west of Shark Bay (April 2012) and three olive ridley turtles (Lepidochelys olivacea) on the Australian shelf of the Timor Sea (September 2012, Fig. 1). Turtle encounter rates were 37 % inside the shallow Dirk Hartog pass (mean depth 11 m) compared with 0 % on the seaward side of the island, and 2.5 % in the Timor Sea (mean depth 113 m). Straight carapace length (SCL) was measured for one olive ridley (70.0 cm, an adult female) and four green turtles (SCL =40.6–89.5 cm). At least two olive ridleys and three greens actively inspected the bait (see electronic supplementary material).