The same thing happened to my wife and I during a whitewater rafting trip down in Costa Rica. We had stopped mid-way in a giant ravine after a long grueling trip. It was in fact around lunchtime but we both had no clue lol. We just were glad to get out of that raft to stretch, walk around, and enjoy the breath-taking scenery. Next thing we know, the guides had flipped over the rafts and had setup atop each raft a complete buffet of food and spirits! It was incredible! Where the heck they had that stuff stowed was beyond me. Utterly amazing. Hot and cold food. A complete surprise. I'll never forget it. 

No shore lunches. But my dad would always buy us pork and beans and some kind of Little Debbie snack cake to take along. When he was still living we carried on that tradition with my daughter.

I've been going to a lodge in NE Ontario for about 30 years.  When we first started going up, the lodge provided a box with pots, pans, utensils, grill top, potatoes, onions, coating mix and a can of bake beans to take with us if we wanted to do the a shore lunch, of course we had to catch the fish.  The standard Canadian shore lunch is fried fish, home fries and onions and baked beans.  Here's a couple pictures of me cleaning a fish, most likely a walleye and, I think, bringing the fillet over to bread it and put it on to cook.

 

Because of a fire risks, some canoers camping on the backside of the island the lodge is on didn't make sure they're fire was out and almost burned the lodge and its cabins down was probably the main reason, they started supplying propane stoves, which took the fun out of doing a shore lunch.  We haven't done a shore lunch since. 

We looked forward to the shore lunch on our trips to Canada.  Fresh fish, potatoes and beans.