I created this for my kids to play with now that the temperature is getting hotter. It could be done cheaper. I spent about $20 on it. This is my first instructable so please bear with me. My trampoline is 14'. I got all my supplies at Home Depot.
I started with two 10' pieces of 1/2 flexible tubing (I think it is used for sprinkler systems). I connected them together with a little coupling and then duct taped the joint. I bought a plug for one end a adapter that went from the 1/2" to 3/4" (forgot to get a picture of). A water hose they said was 3/4". The problem is that the end of the water hose would have to be threaded into this coupling and so I would have to turn the entire water hose. To get around that I bought a quick release connector in the water hose section that allows me to pop the hose on and off much like a connection on air tools.