Meet the site
Spot G is a section of the northern Lonsdale Wall named, according to the Scuba Doctor guide, 'by a local diving identity' and with a reputation for being hard to locate: 'some even say it doesn't exist, but it does.' It lies within a boat-length of The Swim Through and shares the same reef top at about 20 m, but the character of the face is different. Here the wall runs north–south with the deep water to the east, and the limestone has fractured into huge splits and cracks, with whole sections separated from the main wall so that a diver can swim between the parent cliff and the detached slabs.
The listing rates the site 20–40 m and describes it as 'a photographer's heaven' for the fish life and the colour, and that is the right way to think about it: rather than a swim along a face, Spot G is a place to settle at 30 m in a crack, light it, and work the walls. The splits shelter southern blue devils, zebrafish, moonlighters and senator wrasse; giant cuttlefish use them in the winter breeding season; and southern rock lobster are numerous under the ledges. The encrusting life – zoanthids, sponges, ascidians and small gorgonians – is as thick as anywhere on the wall.
The depth range is a genuine 20–40 m, and there is no shallow water to retreat to on the reef top, so this is a site for divers already comfortable with deep Heads walls. It is dived on either slack, and as with the rest of the system a live boat, DSMB ascent and firm turn time are the basic conditions of the dive. Operators tend to put experienced groups here or on the adjoining Swim Through when the shallower sections are crowded, and technical divers use the base of the wall for trimix dives.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Spot G is recorded as Wall in Port Phillip Heads. The listed access is boat. 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.
- Other water users
- Ask about vessel activity, exclusion areas and the agreed surface arrangements.
- Planned depth
- Confirm the intended route and training requirements; the recorded maximum is not a target.
- Water movement
- Ask how swell and local exposure affect the proposed entry, exit and route.
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 Spot G suitable for my certification?
The record lists Deep/Advanced + experience. 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 Spot G 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 blue devil, zebrafish, moonlighter, senator wrasse, giant Australian cuttlefish, southern rock lobster, yellow zoanthids, sponges, ascidians, gorgonians
Location
Northern section of Lonsdale Wall inside the Heads, 12 m west-north-west of The Swim Through; the wall here runs north–south with deeper water to the east.
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.
