We don’t know a lot about the circumstances, but this video appears to be from a whale-watching expedition.
Tourists are watching an angler who is hooking something really big. It could be a huge tuna — or maybe it’s a humpback whale, tangled in his line.
Either way, he realizes it’s too strong to reel in, so he throttles backward. When the seas start pounding his transom, he decides it’s time for a strategy change.