Of course they are factory. Fanfare meant that the plans for the 53' were created prior to the Clean Water Act, and Hatteras then had to add the holding tanks to the plans (not to the boat). For whatever reason, they didn't add them such that the CG was centerline. They could have made the forward tank bigger, but Hatteras is very much about redundancy, so they went with two tanks. Also, maybe that would be too much weight forward.