Had a friend visiting this weekend, and they wanted to do a river tour, which we did, doing the city cruise thing from Greenwich to Westminster. When we got to Tower Hill, the boat pulled up, and eight marine police officers got on, with two police boats pulling up alongside. They politely asked us to move from the back of the boat to the front - when we got to the front, we saw other police asking a group of Asian men to come with them to the back of the boat. They spent about 20 mins questioning them, and searching their clothes and bags. My friend overheard one of the coppers say the captain had called it in. Some people freaked out and demanded to be let off, some people just carried on as normal looking straight ahead and waiting for the boat to leave again (one lady had a panic attack and a crew member gave her a free shot of vodka, which is probably not health and safety compliant, but whatever). Police told us there was nothing to worry about, let the guys go back to their seats, then we were on our way. All very strange and uncomfortable, and I felt awful for the guys who obviously just wanted to to enjoy a nice tour of the Thames.

Have you experienced anything similar recently? Was it mad for the captain to call it in?