OUTSIDE: Most people think of sea kayaking as a mellow activity.
CURGENVEN: Where I live, in North Wales, we have fantastic tidal races—or rapids, as you call them—and we spend a lot of time out there playing and surfing.

How do you get footage?
Initially, I had a big handheld waterproof camera, but it was bulky and made me nervous in rough conditions. Now I have a pencil camera that I can clamp to the front of most kayaks. It's attached to a pole with a ball-and-socket joint that I can adjust from the cockpit. It allows me to get a huge variety of exciting shots.

What's an essential piece of gear for longer expeditions?
I always have a Casio Pathfinder PAG40B-2V watch ($200; casio.com). It's waterproof—obviously!—and it has a barometer, compass, altimeter, and thermometer. There are similar watches available, but I like this one because it has a graph showing how pressure has changed over the past 24 hours, which is useful for weather forecasting. If the pressure is dropping by more than one or two millibars an hour, then it's a good idea to think about getting off the water.

Rumor has it you got arrested in Siberia.
We landed on a beach [in Kamchatka] and this tank came along with eight armed soldiers. They insisted that we break camp and load the kayaks onto the tank and go to their military base. Three hours later, they said everything was OK and drove us back.

CURGENVEN'S THIS IS THE SEA 3 IS NOW AVAILABLE ON DVD AT CACKLETV.COM.