Drill a small hole through the deck and then use a jig saw with the finest tooth blade you can find. It's not a bad idea to find the center of your hole and then cover the deck with masking tape. Then scribe your hole's outline on the tape and cut away. The tape will minimize chipping around the edges. Also make sure that your jig saw blade is squarely aligned in it. Test it on a piece of wood of approximately the same thickness of your deck. Most jig saws are adjustable and most are not square even when the guage says zero degrees. You don't want to cut a tapered hole!
A hole saw, if you can find one (try a commercial supply house), will do the job fine but I strongly recommend the two cut process mentioned above. The hole saw will be kind of expensive for just a one time use. And the above poster was not lying about the amount of torque it'll put on your wrist!
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.