Benchy is that cute little boat that everyone uses to calibrate their 3D printer. [Emily The Engineer] asked the obvious question—why isn’t it a real working boat? Then she followed through on the execution. Bravo, [Emily]. Bravo.

The full concept is straightforward, but that doesn’t make it any less fun. [Emily] starts by trying to get small Benchys to float, and then steadily steps up the size, solving problems along the way. By the end of it, the big Benchy is printed out of lots of smaller sections that were then assembled into a larger whole. This was achieved with glue and simply using a soldering iron to melt parts together. It’s a common technique used to build giant parts on smaller 3D printers, and it works pretty well.

The basic hull did okay at first, save for some stability problems. Amazingly, though, it was remarkably well sealed against water ingress. It then got a trolling motor, survived a capsizing, and eventually took to the open water with the aid of some additional floatation.

We’ve seen big Benchys before, and we’ve seen fully functional 3D-printed boats before, too. It was about time the two concepts met in reality. Video after the break.

Although the types of drones currently dominating headlines tend to be airborne, whether it’s hobbyist quadcopters, autonomous delivery vehicles, or military craft, autonomous vehicles can take nearly any transportation method we can think of. [Clay Builds] has been hard at work on his drone which is actually an autonomous boat, which he uses to map the underwater topography of various lakes. In this video he takes us through the design and build process of this particular vehicle and then demonstrates it in action.

The boat itself takes inspiration from sailing catamarans, which have two hulls of equal size connected above the waterline, allowing for more stability and less drag than a standard single-hulled boat. This is [Clay]’s second autonomous boat, essentially a larger, more powerful version of one we featured before. Like the previous version, the hulls are connected with a solar panel and its support structure, which also provides the boat with electrical power and charges lithium-iron phosphate batteries in the hull. Steering is handled by two rudders with one on each hull, but it also employs differential steering for situations where more precise turning is required. The boat carries a sonar-type device for measuring the water depth, which is housed in a more hydrodynamic 3d-printed enclosure to reduce its drag in the water, and it can follow a waypoint mission using a combination of GPS and compass readings.

Like any project of this sort, there was a lot of testing and design iteration that had to go into this build before it was truly seaworthy. The original steering mechanism was the weak point, with the initial design based on a belt connecting the two rudders that would occasionally skip. But after a bit of testing and ironing out these kinks, the solar boat is on its way to measure the water’s depths. The project’s code as well as some of the data can be found on the project’s GitHub page, and if you’re looking for something more human-sized take a look at this solar-powered kayak instead.