Aloha from the Garden Island of Kaua’i in the Hawaiian Islands. I’m on a much-anticipated family vacation, where my wife, Sarah, and son, Paul, and I are enjoying some spectacular scuba diving (along with my brother, Drew, who took this photograph of a sea turtle we encountered Saturday). When I’m not fishing, diving is my favorite pastime. I enjoy watching fish when I’m not actually casting at them, sometimes for reasons explained in one of last week’s Fly Talk posts. I’ll admit, however, that I much prefer the clear, warm tropical waters over the icy swirling currents of trout rivers.

Last night, I took my rod to cast off a point of lava rocks. I was casting a Clouser minnow at nothing in particular, and truth be told, I didn’t catch anything. But I did see another giant green turtle swim up near the shoreline, poke its head above the surface to check me out for several minutes, then vanish under the foam.

It got me thinking that the real attractions of fly fishing are often the things an angler sees that don’t have any business or interest in casting to in the first place. If you aren’t looking around, after all, you aren’t really fishing, at least not in my mind.

Among my favorite experiences have been watching blue whales spout as I was fishing for mako sharks with Conway Bowman off the coast of San Diego. It was like watching living 737s bend and roll. It’s a unique–sometimes shocking–experience to encounter a brown bear on a river in Alaska. I like watching eagles and ospreys work. River otters are always interesting: they seem to be laughing at me when I fish with that silly stick and string. I’ve had bull sharks bump into the side of my kayak as I was fishing in the Everglades. And a bull moose once stared down Tim Romano, Joe Cermele and I as we were fishing the Colorado River in Gore Canyon. Truth be told, the moose encounter was probably the most unsettling of them all.

But I wouldn’t trade any of that for the world.

I’m wondering what your favorite “sideshow” experience on the water. For the best story in the comment thread below, I will arrange to get an autographed copy of “What a Trout Sees” from author Geoff Mueller and our own Mr. Romano.