Dom Joly: Oh for Okanagan and the awesome Ogopogo

Ogopogo is supposed to live in a huge cave under a scary looking island called Rattlesnake Island

'What is your reason for visiting Canada?" asked the immigration officer at Vancouver airport. I hesitated, then blurted it out. "I'm a monster hunter here to find Ogopogo." She looked at me and I could sense her wondering whether to call security. "Well, the best of luck with that, sir. And your real reason for visiting Canada?"

This was history repeating itself. When I was writing my last book, The Dark Tourist, I was kept at Tehran airport for a long time after I announced, truthfully, that I was visiting Iran to "go skiing". One of the hard and fast rules of immigration officers worldwide is that they don't like you to have visited anywhere interesting or done anything unusual.

I'm currently on the first trip for my new book, Scary Monsters and Super Creeps, in which I'm travelling the world trying to find out more about famous monsters such as the yeti or bigfoot. It's not easy being a monster- hunter. I had no idea what I'd need to take with me, and I feel very unprepared. This trip is definitely a learning curve, and I hope to be far better prepared when I go after bigfoot in November. I'm also interested in the Mokele-mbembe (a dinosaur-type creature) in the Congo. Japan also has a vast array of monsters that I want to go after, including a man who was supposed to have been irradiated in the atomic explosion in Hiroshima and has taken to the nearby hills. For the moment, I have decide not to pursue the "big cat" that is occasionally spotted in the pages of the local Cotswold newspapers on slower news days.

My first quarry is Ogopogo, the lake creature supposedly residing in Lake Okanagan in British Columbia. Ogopogo is supposed to live in a huge cave under a scary looking island called Rattlesnake Island on Lake Okanangan. Locals don't like to go near the place, and I've been told not to mention my destination when renting a boat.

I suppose Tintin had something to do with my interest. As a boy, obsessed with the young cartoon reporter, I had a map on my bedroom wall with pins stuck into all of of his destinations. My two favourite Tintin books, The Black Island and Tintin in Tibet deal with monsters. In Tibet, Tintin comes up against the yeti, while in The Black Island he has to go to a castle on a remote Scottish island that, according to locals, is home to The Beast. On my 12th birthday, my mum gave me Arthur C Clarke's Mysterious World. I've wanted to try to find a monster ever since.

Initially, I was going to start my hunt a little closer to home, in Loch Ness. Unfortunately, I've been there before and managed to annoy quite a few people, so I'm wary of returning. About 10 years ago I went up and, using a large footprint on the end of a broomstick, made a series of tracks around the caravan of one particular Nessie obsessive after he'd gone to bed. Curiously enough, Lake Okanagan has very similar topography to the Scottish loch and is on roughly the same latitude.

Back in Vancouver airport, the immigration officer was still waiting for an answer. "That is the real reason for my visit: I want to try and find Ogopogo." She looked at me without a hint of a smile. "And would this be for business or pleasure, sir?" I replied that it was definitely for pleasure ... for the moment. She paused for a second, and then sighed and stamped my passport.

I had a sighting on the first day. Check this out: facebook.com/photo.php?v=10150419181813487