Pack a picnic, head down Spit Road as if you're going to the northern beaches, and take a left at Mosman's Pearl Bay Rd, then park near the start of the short walking tracks that lead down to a tiny gem of a spot known as Pearl Bay.
You can spread out your goodies on the lovely, shady hillside that overlooks the bay, Middle Harbour and a collection of serenely bobbing vessels including some of the last remaining houseboats moored in Sydney waters.
Walk off your lunch on the Beauty Point Foreshore Walking Track. The bit that leads to Beauty Point / Quakers Hat is enchanting, while the section that meanders towards The Spit is noisier but takes you right past the abovementioned houseboats so you can gawp (discreetly, of course) at the occupants' washing drying in the seabreeze and wonder about who lives in these fascinating floating homes - one of which has been there for 100 years.
Further on, a fledgling saltmarsh will someday provide a home for fish, birds, crabs, molluscs and insects – so the accompanying sign says. Similarly, the seawalls here have apparently been specially designed to look like natural shores in an effort to encourage fauna to the area.
There are several eateries at The Spit end of the walk, all idyllically located and as pricey as you might expect. The Ormeggio restaurant / bar / kiosk is conveniently situated at the back of the Andrew Short Marine boat showroom for anyone wanting a new yacht with their latte...
On the other side of the road / harbour, you'll find the upmarket Harry's Fish Cafe, the Cala Luna Italian restaurant and Orso, whose Sunday brunch menu has everything from eggs benedict and fruit salad to squid ink pasta and scampi tails. The Mosman Rowers Restaurant is back in Pearl Bay itself, as is the cheap and cheerful - and very picturesque - picnic option.