Calculus is traditionally tested, at least in part, by a closed book written examination taken under secure conditions. In March 2020, two-thirds of the way through a vector calculus course, our institution went into lockdown and all teaching and assessment had to shift online. While some teachers insisted that remotely written non-proctored examinations remain closed book, we accepted that this would result in inequity, with some students certainly choosing to flout that rule should it be imposed, to their advantage over their classmates. Driven by circumstance, we were forced to design a vector calculus examination that would be written open book and 'open internet' with access to online calculators and computer graphing packages. Proficiency at vector calculus is exhibited far more in the interpretation of information and effective decision-making than in the computational solving of integrals. In this article, we shall present and discuss our experiences, address the challenge of non-proctored examinations and argue for the merit of open book examinations in an otherwise standard vector calculus course.