The American River in Sacramento is a great place to do some rafting. I've taken a few trips down the river with a commercial rafting company and I must say that it is a real blast. One of the reasons this river is so fun is that there is always a good water fight going on with other rafters. I've tried various toy soakers and squirt guns, but these usually don't even make it through the trip without breaking. So, I set out to build my own syringe type blaster. The first rev of the design was built with 1-1/4" PVC pipe and worked out quite well, but it was time consuming to make and required the use of metal working tools to make the piston assembly. I was also looking for somehting bigger, and I finally found a design that is simple to make, cheap, reliable, and works incredibly well. I can't take credit for this design, and I don't know where it originated, but Kudos to whoever came up with it!