Intentionally timing the "Squirting Elephant" to soak yourself or passengers. (There is also a way to manually activate the "Squirter" on an unsuspecting skipper by hitting the animatronic's reset button, located inside the large rock where the Elephant Pool waterfall is (the rock is actually a hollow building!)
Shooting boats with a maintenance hose that sits behind the gorilla camp.
Having fun at the Schweitzer Falls bend. This actually needs some explaining. Sometimes a skipper will take out an empty boat to prevent the fleet from backing up and keeping the boats evenly spaced. This boat is called a "deadhead". When that solo skipper passes Schweitzer, he'll eventually get an audience when another boat passes in the other direction. Skippers have been known to dangle their bodies off the edge of the boat, playing dead, with a spear jammed in their back. Others will sit indian-style like a monk on top of the boat's smokestack. Sometimes the "deadhead" skipper gets a prank pulled on HIM. Other skippers will climb on TOP of Schweitzer falls with a giant bucket of water. As the "deadhead" passes underneath (the 2nd time past it) the skippers will dump the bucket of water on the boat from above. Oh yeah, one more "deadhead" story. As a tribute to Jerry Garcia on the night of his death, the crew sent a unmanned "deadhead" (obviously because of its coined name) around the river after park closing. A skipper jumped inside, set the throttle, and leaped back out as the boat pulled away from the dock. A few skippers even heard the ghost of Jerry out on that boat, singing to the animals. : )
Speed Trap. (This is by far my favorite prank... but, unfortunately, a hand-me-down story from the guys who did it) After dark, two skippers would take the skiff (a small maintenance boat w/ an outboard motor) out on to the river and hide around the corner from Schweitzer Falls. As a Jungle boat would pass by and head towards the Nile Elephants, the skiff would zoom around the corner behind the boat. The skiff operator would hold up red-and-white flashing police lights purchased at Radio Shack. He'd demand the Jungle boat to stop, where then the host skipper was required to do a field sobriety test. Obviously he'd fail. So the arresting officer would make the Jungle skipper ride back home in the skiff while that officer would finish giving the guests their tour.
Some skippers would do the spiel about the attacking natives and then yell to the animatronics "Hey guys, I said throw the spears! Next time you better do it, OK? Now get down in the bushes and hide again... I'll be back later!" At that moment the animatronics appeared to crouch down and hide in the bushes as he commanded... a result of the computer resetting itself for the next boat.