According to Wiki, a B-Roll “is the supplemental or alternate footage intercut with the main shot in an interview or documentary.”
In this case, the alternate footage shows aircraft being launched and recovery aboard USS Enterprise, the U.S. nuclear flattop retired on Dec. 1, 2012.
Unlike many other videos, the B-Roll of Big-E contains raw footage: it does not include any annoying background music giving you the opportunity to hear the real sound of Blue Water Ops.
H/T to Matt Fanning for sending us the link to the video