Created in Photoshop 2D as a paintover, using mouse and clone tool using patterns from real charcoal images also includes a lot of filters, layers as well etc..

Image used for the paintover can be found here:

https://www.spatialsource.com.au/surveying/revealed-2015-discovery-located-spanish-galleon-with-22bn-cargo

And is under the license Wikimedia commons:

Wikimedia Commons only accepts free content, that is, images and other media files that are not subject to copyright restrictions which would prevent them being used by anyone, anytime, for any purpose.