Turns out that National Geographic hosts these assignments open to anyone. I found out about this just in time to get excited about their soon-to-be-closed assignment, "the Pool", an appropriately Summer-themed selection.
The curator, Sherry L. Brukbacher (a photo editor with NatGeo), quotes Maria Popova of Brain Pickings in the contest's description: "a wordless masterpiece of space, scale, and silence converging [in] an underwater world of wonder just beneath the reflective surface of ordinary life.” These words describe a work of Jihyeon Lee's children's book, Pool.
This led to the concept and subject of my shoot immediately flooding me with possibility (please forgive the pun...or not, I leave the concept of humor to you). So I reached out to the mother of an adorable young model I've worked with countless times modeling for Bay Area Wedding Fairs and booked the shoot for tomorrow afternoon. I went to Best Buy to purchase an underwater camera (as water-safe housings for my Mark III push $2k, not including modifiers for the lenses themselves!) and am so excited to drive to Modesto tomorrow for my shoot with little Scarlet!