 Complete the following phrase:  As cameras and sensors have evolved and vehicles have become more agile and simple to pilot, ROVs have become popular particularly with documentary filmmakers due to their ability to access deep, dangerous, and confined areas unattainable by divers. There is no limit to how long an ROV can be submerged and capturing footage, which allows for previously unseen perspectives to be gained. ROVs have been used in the filming of several documentaries, including Nat Geos Shark Men and The Dark Secrets of the 