2.4.4.2  Clearing an Area

If you are clearing an area based on a side scan image the goal will be to find the possible targets of concern that might have been located using the side scan. The ROV can then be sent to investigate those targets closer and identify them. In this case, the coordinates can be entered and the ROV sent to each targets location directly rather than navigating a pattern through a region. In general all targets will be able to be inspected using this technique. If you are unable to locate a target, or you are clearing an area using only the ROV, you will need to apply a region and this Wide Area Search SOP.

If a suspected target is found, you should set an MOB point (ROV position, heading, attitude and depth) and mark the target with a Marker and take a snapshot. This will provide some redundancy and if you lose sight or sonar image of the target, you can navigate back to the point where you know you were able to observe it before.

"A bird in the hand is worth two in the bush." It is usually best to inspect and identify possible targets when they are first observed rather than to mark numerous targets and wait until the end of the mission to go back to review them. You can easily restart the mission where you left off or by right-clicking on any waypoint and selecting Go to Waypoint or by clicking on the Skip button.

If you plan to clear the area on a periodic basis, you can save the mission, which will save the Markers and MOB points in addition to the waypoints. Then, when clearing the area again in the future, you can look for exceptions knowing what was there already and does not need to be investigated in detail.

Obviously, how to deal with unknown objects that are found is up to the user and beyond the scope of this manual.