From the 50's, when tailfins were required for designs to sell (it seems)

From http://www.fiberglassics.com/galleries/bitb/ via http://stipistop.com/

If you wanted a boat that had the beauty of automotive design, but without the half way mutant looks of the Amphicar, or the Isetta boat http://justacarguy.blogspot.com/2009/02/smile-this-coudnt-have-actually-went-in.html then thse boats look really good.