My attempt at freehand model a Capybara fish portal in FreeCAD.
Print it with 10-20% infill to make it float.
I have a few other designs of fish portals and plan to make more, check them out if you want :)
If you have a specific shape in mind, send me a message and I'll try to make it for you.
if you like my work, consider donating :)
https://ko-fi.com/jobis
The author marked this model as their own original creation.