Meet the site
London Bridge is the famous sandstone arch of the Portsea back beach, a calcarenite span left standing on the wave-cut platform below 30–40 m bluffs, and the diving is on the reef and gullies that surround it. The Scuba Doctor lists it as a 5–7 m shore dive for Advanced divers, and the depth is misleading about the difficulty: this is a Bass Strait rock-platform entry where the sea, not the diver, decides whether a dive happens. On the rare flat days the site is superb. The intertidal flats either side of the arch are cut by gullies that lead out to broken limestone reef, undercut into ledges, small caves and swim-throughs by the same weathering that carved the arch, all roofed with kelp and crusted beneath with sponges, bryozoans and jewel anemones. The shallow bay to the west holds gullies full of fish, and the offshore reef carries schools of sweep and old wives, zebrafish, magpie perch, blue-throated wrasse, leatherjackets and long-snouted boarfish, with southern rock lobsters and abalone in the crevices and Port Jackson sharks and draughtboard sharks resting under ledges. Weedy seadragons drift in the kelp, and fur seals from the Heads occasionally investigate divers. The site's history is grim – the 1967 disappearance of Prime Minister Harold Holt while swimming at Cheviot Beach a kilometre west is the standard warning about this coast – and its exposure is total: it is rip-prone, surgy even on calm days, and within reach of the tidal streams of The Rip. It belongs to experienced divers with surf-entry skills who have watched the sea for a while before gearing up, ideally with someone who knows the gullies. For them it is one of the most dramatic shallow dives in Victoria; for everyone else it is a place to snorkel the inner gullies at low tide on a glassy day, or to admire from the lookout.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
London Bridge, Portsea is recorded as Shore/Rock Platform in Mornington Peninsula. The listed access is shore. Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
Topics flagged by the stored research
These are questions prompted by the existing notes, not a verified or complete hazard assessment.
- Current and timing
- Ask how the operator assesses the current window for the actual route. Historical tide notes are not a departure instruction.
- Water movement
- Ask how swell and local exposure affect the proposed entry, exit and route.
- Overhead environments
- Ask whether the plan stays entirely in open water. A wreck or cave listing is not permission or training to enter.
Historical access notes exist for this record, but have not been independently verified for current use. Request current directions from the operator or site manager rather than following an old entry description.
Questions, answered
Is London Bridge, Portsea suitable for my certification?
The record lists Advanced Open Water. That does not establish suitability for every route or day. Share your training, recent experience and equipment needs with the operator and ask about the specific proposed dive.
Can I book London Bridge, Portsea through YouDive?
YouDive is an independent research directory. Contact an operator directly to confirm whether it currently runs the trip, the inclusions and the booking terms.
What you might see
Southern rock lobster, blacklip abalone, weedy seadragon, Port Jackson shark, draughtboard shark, sea sweep, old wife, zebrafish, magpie perch, bluethroat wrasse, long-snouted boarfish, leatherjackets, jewel anemones, sponges and bryozoans, Australian fur seal (occasional)
Location
Natural calcarenite arch and rock platforms at the end of London Bridge Road on the Portsea ocean coast, 30–40 m bluffs behind, 1.5 km south of Portsea village.
Facilities nearby
National park car park at the end of London Bridge Road; no toilets or water; cafés and Bayplay dive shop in Portsea 1.5 km; air fills at Bayplay or The Scuba Doctor (Rye).
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
scubadoctor.com.auscubadoctor.com.auRecord updated 26 Sept 2026. Source claims are being reviewed.