Over on Thingiverse Devon Jones has been working on Openforege an extensive range of open source dungeon terrain tiles. I printed up a bunch last year but realized that I would never have time for RPGs so they went to a new home.
However, earlier this year Mr Jones released a set of rowboats and dinghies which will be perfect for the canals of Mars. There are a few technical tweaks needed but below is the first set of prints.
I like the small boat especially since it is just different enough to say not of Earth. The larger may well get used as a landing craft by Earther forces or maybe even Oh'ktava'ns Marines.