Caithness Petroleum Limited : Helmsdale, Forse, Baremore and Burrigill 2nd and site surveys : UKCS blocks 11/23, 11/24, 11/25, 12/21, 11/27, 11/28, 11/30, 12/26, 17/2, 17/3 : marine mammal observations and passive acoustic monitoring report.: Helmsdale, Forse, Baremore and Burrigill 2nd and site surveys : UKCS blocks 11/23, 11/24, 11/25, 12/21, 11/27, 11/28, 11/30, 12/26, 17/2, 17/3 : marine mammal observations and passive acoustic monitoring report. (2011)