Martha Spencer clings to the tall yellow leg of the oil rig, her speargun tucked close to her torso, the waves smashing violently against her.

The seas are rough today, a sunny and otherwise pleasant Friday in June. But a heavy breeze moving across the Gulf has brought choppy waters, with swells of up to 5 feet — far from ideal diving conditions.

With every passing wave, Spencer is pushed harder into the rig but manages to hold on, steadying her breath while clutching steel beams covered in barnacles and rust before she's ready to make her descent.

A couple of deep breaths and then she's gone...