Remotely operated vehicles (ROVs) are vehicular robotic systems that are teleoperated by a geographically separated user. Advances in computing technology have enabled ROV operators to manage multiple ROVs by means of supervisory control techniques. The challenge of incorporating telepresence in any one vehicle is replaced by the need to keep the human “in the loop” of the activities of all vehicles. An evaluation was conducted to compare the effects of automation level and decision-aid fidelity on the number of simulated remotely operated vehicles that could be successfully controlled by a single operator during a target acquisition task. The specific ROVs instantiated for the study were unmanned air vehicles (UAVs). Levels of automation (LOAs) included manual control, management-by-consent, and management-by-exception. Levels of decision-aid fidelity (100% correct and 95% correct) were achieved by intentionally injecting error into the decision-aiding capabilities of the simulation. Additionally, the number of UAVs to be controlled varied (one, two, and four vehicles). Twelve participants acted as UAV operators. A mixed-subject design was utilized (with decision-aid fidelity as the between-subjects factor), and participants were not informed of decision-aid fidelity prior to data collection. Dependent variables included mission efficiency, percentage correct detection of incorrect decision aids, workload and situation awareness ratings, and trust in automation ratings. Results indicate that an automation level incorporating management-by-consent had some clear performance advantages over the more autonomous (management-by-exception) and less autonomous (manual control) levels of automation. However, automation level interacted with the other factors for subjective measures of workload, situation awareness, and trust. Additionally, although a 3D perspective view of the mission scene was always available, it was used only during low-workload periods and did not appear to improve the operator's sense of presence. The implications for ROV interface design are discussed, and future research directions are proposed.