It's not much to look at, but it is possibly the first 3D printed boat, helmed by Matt Rogge of the University of Washington' Washington Open Object Fabricators club. It's interesting for a number of reasons; 1) it actually floats and came in second in a race;
"Frankly, milk jug material is an awful material to work with," he said. "It shrinks, it curls, it doesn't want to stick to itself. Overcoming all those parts of the problem was part of the achievement."
From the WOOF team:
WOOF group has spent the last two months researching. engineering, extruding, printing, and dumpster diving for the greater good. WOOF submitted the first 3D printed milk jug boat into the Seafair Milk Carton Derby. Not a simple task, they hacked a 4′ x8′ plasma cutter, slapped a homemade extruder on, and dealt with 2% shrinkage, to produce a beautiful boat. The boat weight is 40 lbs (~250 1 gallon Milk jugs) supports 150lbs, yet cuts through the water like a canoeyak.
Closup of the boat. You can tell that this was not easy to work with.