My senior engineering project in college was the development of a GPS-guided robotic boat for recreational purposes. Our team consisted of three electrical engineers with very little machine design experience (this was just the first of many aspects of this endeavor which were hilariously ill-thought out), so we ended up bashing together a makeshift thruster out of plumbing fittings and an electric trolling motor, with predictably awful results.

Seeing this brought back memories. A self-contained thruster unit intended for integration into a larger robot might just have saved our project, had it been available four years ago.