While the Merlins departed for base after the arrival of HMS Prince of Wales, the Wildcat wasn’t going anywhere. I suspect that they had a film unit on board that was recording the arrival of the carrier strike group, so they were getting aerial shots from different angles. A number of times they flew out of the harbour and then turned to run back in. It is possible that this was necessary for a shot that they were trying to get but my suspicion is that the parents of the pilot were in the crowd and a few flybys were for their benefit instead. Who knows???