He got an idea of the depth of the shear layer by observing the extent of the sideways turbulence at the <e1>stern</e1> of the <e2>boat</e2>.
He got an idea
He got an idea of the depth of the shear layer by observing the extent of the sideways turbulence at the stern of the boat.
<triplet> stern <subject> boat <object> Component-Whole(e1,e2)