This is my printable version of a springer tug - a small rc push boat - scaled down to 190mm by 83mm.https://www.youtube.com/watch?v=PZ92AC9zggQNote: all designs have to be scaled down 1:10 before printing. I work mostly with SketchUp which has trouble dealing with smaller objects (ie: extrusion, binary operations tend to fail when dealing with sub 1mm^2 surfaces).I've printed it in ABS as I find it easier to make ABS prints watertight: I just brush them with acetone. But it should probably work in PLA too once you get the hull watertight.You'll need some RC equipment if you want to actually get it going, obviously.There's a bill of material on my site, as well as pictures and videos of the thing.==> http://rc.noalia.fr/boats/microspringer/