Hawkesbury R is a magical cruising ground! Deep water, few shoals, and a short day-sail to Sydney Harbour. You'll love it!
Regarding showers, get yourself a 1-litre pump-up spray bottle, you can have a full shower
, including hair-wash with 1 litre of water!
I cruised the E Coast (Oz) for 10 years, and this was my shower
, when I couldn't find a creek or waterfall nearby.
Be sure to explore kuringai national park, you'll find ancient rock-carvings scattered about, see koalas in the wild, and find isolated, picturesque anchorages. All within 20 miles of Australia's biggest city.
And, when you're finished with Hawkesbury, you can sail, in day-sail hops, all the way up to the Witsundays, surely the best cruising-ground in the World!