The group included a friend, Matthew Frost, who decided to pick up his friend Maria for the photo above.
He was feeling very pleased with himself. He'd made up a joke.
"I'm on a new keep fit regime," he was telling anybody who'd listen. "I'm running up rigging, climbing along masts and jumping off gangplanks."
Then came the punchline: "It's called pi-ra-tes," he'd say. He pronounced pirates, of course, with the same number of syllables and to rhyme with pilates. It made me laugh.
Amongst the throng there were also some fellas who'd had a few beers before coming on the tour. This meant they sprinted away at the end to find a toilet, any toilet. It's odd but sometimes people forget that two pints before an event makes the final moments of an eighty minute tour difficult.
Still they were well-behaved despite the alcohol.
One man, in this group and in his thirties, took off his shoes when I said the tunnels could be muddy, because, as he said "I'm too tight to get my new trainers dirty even though they weren't expensive."
Down in the tunnel, one guest, Phil Rawnsley, captured some excellent pictures. The one of the doll - a mysterious presence in the tunnel - is particularly spooky.