Mine's made from an 8mm fibreglass blank, eurethaned into an air hose fitting, reinforced with a 4" length of poly pipe filled with eurethane.
A safety flag from one of the safety shops sits atop, and Xmas trips the santa flag goes on too : )
Clicks into the female fitting on the front nudge bar and sits about 3.5m total off the ground.
I'll find a couple of pics.
Like mentioned by others a fishing rod blank works great, but they were hard to find and I needed one quick for first beach trip, local fibreglass place had the 8mm rod.
It's done 5 or 6 testing sand trips, including some bumpy dunes, and it is hanging in there nice an solid.