Hearn Road is the second of the five creek gullies that give access to the Mount Martha cliff coast, the 8 km run of low sandstone and basalt cliffs between Balcombe Point and Martha Point that The Scuba Doctor lists as five separate 3–5 m shore dives. Its source page adds nothing to the shared description beyond its position and its 'fairly easy track access', and a diver should expect exactly what the neighbouring gullies offer: a shallow platform reef at the cliff foot with ledges and undercuts a metre or two high, boulder falls from the cliff, brown algae and Sargassum on the rock and seagrass in the sandy gaps, shelving to about 5 m within a hundred metres of shore. The fish are those of any rocky shore on the eastern side of the bay – magpie perch, old wives, zebrafish, leatherjackets, hulafish and bullseyes under the ledges – with decorator crabs, small octopus and abalone in the crevices, fiddler rays and flathead on the sand and giant cuttlefish coming inshore in winter.

What distinguishes Hearn Road in practice is its position: it sits in the middle of the northern pair, far enough from Balcombe Creek to escape the worst run-off and close enough to Deakin Drive (820 m) and Burdoo Way (640 m) that a one-way dive to either neighbour is a realistic option on a calm high tide, with a car left at each end. The Mount Martha gullies are for self-sufficient divers who enjoy unstructured exploration of unvisited reef, for local snorkellers, and for nobody who needs facilities, depth or a defined objective. They are exposed to every westerly, entered over slippery rock, and served only by residential street parking.

On a still winter morning with an easterly, however, Hearn Road gives clear water over several hundred metres of reef that almost nobody has looked at, ten minutes from Mount Martha village.

From Mount Martha village follow the Esplanade south along the cliff top for about 2.5 km to Hearn Road. Park on Hearn Road or the Esplanade – residential streets with no formal car park – and take the walking track down the creek gully to the shore, 100–200 m with a moderate climb back. Enter over the rock platform at the gully mouth at high tide and swim out to the reef in 3–5 m.

Exit at the same gully or, in calm weather, at Deakin Drive or Burdoo Way along the shore.

The Mount Martha cliff coast faces west-south-west and is fully exposed to westerly and south-westerly winds, which raise a shore break over the rock platforms and make the gully entries slippery and surgy; anything above 10 knots from the west quarter is a poor day. Dive on easterly or north-easterly winds, at or near high tide so that the inshore platforms are covered. There is no current.

Visibility drops for a day or two after rain when the gullies run. Summer sea breezes arrive most afternoons, so mornings are the reliable window.

Enter at the gully mouth at high tide, descend as soon as there is 2 m of water and swim straight out to the 4–5 m reef edge, then follow the rock parallel to the cliffs with the shore on one side for a fixed time or gas fraction. Turn, return along the same line slightly shallower, and surface at the gully.

No regular operator – independent shore divers and snorkellers only.