They're frequently seen off the coast of NSW, and probably elsewhere around Australia as well. Back in June 2010 one came ashore at Lennox Head, between Byron Bay and Ballina, causing considerable damage We were living there at the time and, while we didn't suffer any damage, others were not so lucky. A total of 12 dwellings were destroyed, or so badly damaged that they were later demolished, and many others suffered extensive damage. It was only small, about 50 metres in diameter, but the power of it was incredible. A total of five waterspouts were seen off the coast at the same time, but only two came ashore. The other went into coastal heathland, so didn't cause any property damage.
The attached photos were taken by a resident of the village who captured the twister as it crossed the beach. If you look closely at photo 3 you can see flying debris near the base of the column, and in photo 4 the second twister can be seen as well, crossing the beach near the right edge of the photo.
Peter.