I had originally hoped to get into this hobby (and this is an entire hobby into itself) through a kickstarter almost four years ago (supposedly it is ready to start manufacturing once shipping costs come back down to a reasonable level). Last month I went ahead and bought my first 3D printer - and Ender 3d v2.
After my suggestion on making a compact turn marker for Armada, a reader from Australia (with his own blog here) took the idea and made a version, posting the link in a response to my post. This was one of the first things I printed - Compact Turn Marker. A bit more searching on thingiverse and I found a bunch of printable armada terrain.
This set has 7 islands, 4 sand bars, a harbor, and 4 rocks. The islands are designed to be printable in 'vase' mode - which is basically upside down and hollow.
There is one Extra Large Island. This is about the size of the combined cardboard harbors from the starter. All of these are about half an inch tall.