Low, consistent hover over the sea can lead to salt water ingress which has, for me, in the past lead to engine surge. As VVHA suggests, not unusual just a little more 'exciting' than normal.
Also turbulent conditions whilst in the hover with strong cross winds relative to the aircraft can cause upset of the air intake on the downwind engine leading to surge. (I seem to remember that the maximum sideways taxi speed of the Seaking was set at 30kts due to this problem.)
Nothing too exciting.
But never let that get in the way of a good Jurno story.
