The retinal prosthesis test device is comprised of a thin wafer of glass made from nanochannel glass with very small channels perpendicular to the plane of the wafer filled with an electrical conductor forming microwires. The, rotational stabilizing locking apparatus may be a locking cap that includes a central body having a surgical aperture extending from a first side of the central body to a second opposed side of the central body. The electrical lines each have an enveloping insulation. The power installation can make a relatively large amount of power available even when the flow speed of the marine current is relatively low, for example, in the region of 1. In order to deliver fluid to the doctor retaining and adjusting element, the doctor retaining and attaching element includes a fluid driven actuator connected by tubes to a duct in a section bar on the transversal support beam.