Robert Indiana kept a series of illustrated journals during the late 1950s and 1960s, in which he discusses the development of his work as well as his daily life on Coenties Slip.

In his journal entry for July 20, 1962, Indiana records that it was dawn before artist Barrie Bates (now known as Billy Apple), who had come over to work on metal Indiana had given him, finished scraping his hearts. Meanwhile, he finished applying the second coat on the larger orbs in the dials of Marine Works. Indiana then went to bed and woke up at 2:30 p.m., going down to a "lonely loft," as J. (his partner, fashion designer John Kloss) had gone to the Hamptons. 

Indiana records going uptown to the Museum of Modern Art and picking up a catalogue of the collection, in which he was included. He writes "Ellsworth [Kelly] and Jack [Youngerman] were not reproduced: possibly my first slight edge over those Slippers." 

He also notes that he did more work on Marine Works, applying the first layer of gesso on the small circles, the work "becoming more complex each day now."