Little Av is what Avalon locals call the southern corner of their beach, where a rock platform, the ocean pool and a shallow reef sit beneath the headland that separates Avalon from Bilgola. Vizzbud describes it as 'a shallow rock and boulder reef ... a patchwork of low boulders, short walls, kelp and sand channels with small overhangs', 7 m on average and 10 m at most, and rates it an Open Water site suited to newer divers and relaxed dives. It is one of only a handful of shore dives north of Long Reef with any published description, and its shallow, broken structure makes it a snorkel as much as a dive.

The reef holds the regular cast of Northern Beaches shallow rock: Port Jackson sharks under the ledges in winter, eastern blue groper that follow divers, Sydney octopus in the crevices, eastern fiddler rays on the sand channels, old wives, crimson-banded wrasse and morwong over the boulders, and, in the kelp, seahorses and nudibranchs for those who look slowly. Sea urchins pack the shallow rock. Visibility is best on winter westerlies and drops after rain or a run of north-easterlies.

The dive's limitations are exposure and depth: south-east swell breaks across the reef and makes the platform slippery and the corner a surf zone, so it is a small-swell, early-morning, high-tide proposition, and there is nothing deeper than 10 m. Parking is scarce on weekends. Little Av suits Open Water divers and snorkellers living on the upper Northern Beaches who want a local reef without driving to Manly, and it is an easy, pleasant dive on the right day.

Details are from Vizzbud and should be confirmed locally.

From Barrenjoey Road, Avalon, turn into the southern car park off Barrenjoey Road at the southern end of Avalon Beach (limited; street parking fills quickly on weekends). Walk 100 m to the southern corner of the beach beside the Avalon rock pool. Enter from the sand in the corner or, in small swell, from the platform beside the pool, and swim out over the reef that runs south-east under the headland.

Exit at the same corner, timing it between wave sets.

The beaches between Narrabeen and Palm Beach face east to north-east and are open to the full Tasman swell; anything over about 1 m from the north-east or east makes the rock-platform entries a wash zone and puts surge across the shallow reefs, and a southerly swell wraps around the headlands. Choose mornings with under 1 m swell and a westerly or light north-easterly, on the top half of the tide so the platform edges are covered. Visibility is 5–12 m on winter westerlies and drops after rain when the lagoons open.

There is no dive shop north of Brookvale except Dive Spear and Sport at Mona Vale, so fills and advice are limited; these are independent divers' sites. Little Av is exposed to south-east swell and is one of Avalon's surf breaks; Vizzbud advises small swell with westerly or north-westerly winds and an early-morning high tide.

Enter in the southern corner, descend over the boulders at 3–4 m and follow the reef south-east under the headland through the sand channels and short walls to 8–10 m, checking the overhangs for PJ sharks and octopus; turn at half air and return along the inner edge of the reef through the kelp to the corner.

No operator; independent local divers and snorkellers. Fills at Dive Spear and Sport, Mona Vale.