I didn't understand your reference to prop aeration muddling acoustic links between the ship and the ROV.
I phrased it badly. I meant that the USBL link, which is used by the ship's DP system when in follow-sub mode, gets corrupted and the ship starts overcontrolling and becomes more and more divergent.
An ROV can easily come to a dead stop, from a cruise speed of two or three knots in a matter of two or three metres. A 4,000 ton ship cannot. The DP system will command more and more thrust in an attempt to maintain station and that's when you get loss of acoustic link between the USBL and the sub. The ship can easily move out many tens of metres and start dragging the umbilical so much that the ROV itself can be jerked around. The tail starts wagging the dog and dogs don't like that. They bark and get quite snappy. The ROV crew blame the bridge crew and the bridge crew blames the ROV crew.
It can happen quite easily when, for example, the ROV suddenly encounters a snagged fishing net and has to make an emergency stop. It can also happen when the ROV suddenly finds an orange box on a job like this one!