Looks like ghost ships or jut plain rusting hulls of some sort of ships. Same parameters as and
Made in Mandelbulb 2D
Here are tutorial links and the link for the free program. If you need any assistance, you can just note me, I help when I can...
The tutorials were written using older versions of MB3D, so the interface has changed. But if you carefully look around in the same areas I indicate in the screen shots, you can usually find things, sometimes under tabs that weren't there before...