Three focal mother-calf pairs (dashed line) in before, during and after phases with the research vessel approaching (solid line) at 800 rpm (~1.5 knts) during control, medium and high noise treatments. Details of these CEEs are: (A) control: mother resting/logging the entire duration drifting with the incoming tide (flow from ~north to south), closest point of approach 97 m, (B) medium: mother logging before, mother logging during, mother peduncle dove underwater after, high tide, closest point of approach 95 m, (C) high: mother logging before, mother logging during until closest point of approach then peduncle dove underwater and swam away slowly just under the surface of the water, mother logging after, outgoing tide (flow from ~south to north), closest point of approach 95 m.