A fixture for performing visual inspections of the underside of the top guide of a boiling water reactor. The inspections are performed in the reactor vessel, under water, and includes a framed structure that rests on top of the top guide and supports a wheel track within a fuel assembly opening in the top guide, that follows the contour of the opening. A camera support, suspended from the frame, is then remotely, manually rotated to follow the contour of the wheel track as the fixture maintains the camera at a fixed angle and known constant distance from the underside of the top guide.