Planning to be out on the water? Print this floating buoy keychain to keep your keys or other small belongings safe!

Keys can fly overboard in an instant, so it's vital to have some sort of floating attachment to keep them from darting to the seafloor. This buoy has a volume of 49375 cubic mm and weighs 15.40 g (with PLA filament and my print settings). I used this to calculate the maximum weight it can keep afloat; at least 35g (1.25oz), and that's without factoring in the buoyant force acting on the keys. You can, of course, scale up the print to allow for even greater payloads!

I modified my default print settings to find the perfect balance between safety and light-weightiness:

• 3 wall layers ensure no water can seep into the print.
• 10% density cubic infill creates closed-off pockets to prevent flooding in a worst-case scenario, while keeping the buoy as light as possible.
• Small layer heights and slower printing speeds contribute to a clean and water-tight print.

I also recommend printing with a brightly colored PETG filament, although PLA will work just fine as well.

Enjoy!