A-Bay Reef lies off Alexandria Bay, the east-facing beach inside Noosa National Park between the Noosa headland and Sunshine Beach. The Noosa kayak-fishing community lists its mark as 26°23.273'S 153°07.850'E, and nearby 'Doggie Beach Reef' is listed just to the south. There is no published dive guide for the reef.

What is known is geographic. Unlike the Laguna Bay reefs, Alexandria Bay faces the open ocean, so the reef is exposed to the south-east trades and easterly swell and can only be dived on genuinely calm days. In return, it lies away from the Noosa River plume, so visibility is often better than at Jew Shoal. The rocky shoreline of Noosa National Park, which Scuba World lists among the Sunshine Coast's snorkelling headlands, suggests a similar rocky-reef habitat offshore – boulders and ledges with algae, soft corals, sponges and subtropical reef fish.

This is a site for local divers with a boat or dive kayak and knowledge of the Noosa bar. Visitors will get a better experience at Jew Shoal with SubSurface Scuba. Anyone who does dive A-Bay should be aware that the adjacent beach is unpatrolled with strong rips, and that boat access is the only practical option. On the right day – flat seas, a light westerly and a rising tide – it offers a quiet, rarely visited reef within sight of the national park.

Noosa's reefs are reached by boat. SubSurface Scuba runs Jew Shoal double and triple dives (about 20 minutes' boat ride to the shoal). Private boats launch at the Noosa River ramps (Noosaville/Munna Point or Tewantin) and must cross the Noosa River bar at the river mouth beside Noosa Heads – a shallow, shifting bar that is hazardous in any swell and best crossed on a rising tide in daylight.

From the bar, run east around Noosa Heads and south to Alexandria Bay – about 10-15 minutes. The Noosa kayak fishers' mark is 26°23.273'S 153°07.850'E. Alexandria Bay itself is reached on foot via the Noosa National Park coastal track or from Sunshine Beach, but there is no practical shore entry for divers with gear.

Alexandria Bay faces east into the open ocean, unlike Laguna Bay, and is exposed to south-easterly trades and easterly swell; the beach is known for strong surf and rips. Dive only on calm days with small swell and light westerly or south-westerly winds, typically winter mornings. The Noosa bar crossing adds a further swell limit.

Visibility is generally better than inside Laguna Bay because the site is away from the river plume.

Anchor in sand off the reef on a calm day, descend and follow the reef edge in a loop back to the anchor, keeping well away from the surf line.

No regular dive operator – private boat or kayak divers only.