In a scene from the second episode of the TV miniseries Top of the Lake, the lead character (a New Zealand police officer) discovers a dead body floating in the sea. She does not enter into the water, but calls for her male companion, and shouts instructions:
Don't touch him… all right, just bring him into shore. I'm going to have to stay here, I'm OCB.
In a further scene she tries entering into the sea, but experiences sth. that looks like a panic attack and is forced to draw back.
Though I found a couple of terms called OCB, they do not make any sense in this context.