As modeled, 'crazy diamond', (and its refinement, 'a clam on stilts'), have an elliptical, pi to one, height to width ratio ;

(in cross-section at the curves' center), which is attenuated to one to one at the ends .

When being towed to collect oil, such a shape might not trap it as well as a curve with a waist, which should create a rolling eddy in front of it .

Three options for waisted center-cross-section curves are shown below, (together with a pi to one ellipse, as before, at right) .

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At left and center-left are curves formed by the cosine-method blending of paired ellipses, (one positive and one negative, having a height to width ratio of pi/2 to 1), with parallel vertical lines .

The gap between these lines, (which, like the ellipses, exist as part of the overall form but are not visible independently), is 1/pi in the figure at left, and 2/pi in that at center-left .

For the figure at center-right, the blend is between two circles of radius 1, and parallel lines with a gap of 2/5 ; following which, both height and width are multiplied by pi/2 .

If one of these revisions were to be applied, (and if the design is to be built), it should improve the model's ability to control that oil it gathers .