So, earlier I suggested the Grumman Widgeon/Gosling (admittedly tongue in cheek) but, out of curiosity I started digging around to see what the Widgeon contributed to the war and as hard as I have tried I can find nothing other than that it served in the Royal Navy. In fact, its importance to the war effort was so inconsequential that Grumman was able to start building new civilian versions again before the end of the war. Apparently, it was fairly underpowered. It could be modified to carry a 200lb depth charge which is useful for patrol. However, other than a mis-identified kill in the Gulf of Mexico it appears to have no record of distinction. And isn't that the definition of worst? To have been in the party and done nothing. Here's a nice image of a restored Widgeon/Gosling in Royal Naval colors.