This is not perfect, but it is fast, providing smooth transitions but a slightly unequal wall thickness.
1: Place a conoid object to the correct width and depth of the element to be replicated. 180 degrees sweep.
2: Place another conoid beneath it to match, making a complete cone.
3: From a top view in the 3D window, SAVE the two conoid elements together as one BINARY library object.
4: Substitute this new object for the two placed conoids.
5: Reduce the vertical scale suitably - the binary object is elastic.
6: Use a hole in a slab to create the prow radius using SEO.
Dwight Atkinson