Meet the site
Cape Spencer is the southern tip of Yorke Peninsula, where the lighthouse stands above cliffs that drop into the meeting of Investigator Strait and the entrance to Spencer Gulf. The Marine Life Society describes the dive below the lighthouse as vertical drop-offs, undercuts, holes and caves in about 10 m, with caves that cut right through the point and blowholes 8-10 m long. The limestone here is sculpted by constant swell, producing a dramatic underwater landscape of walls and tunnels. The walls carry sponges, gorgonians and ascidians in the sheltered undercuts, while kelp dominates the tops. Fish life reflects the exposure: western blue groper, sweep, silver drummer, old wives, magpie perch and blue devils, with seals from the nearby Althorpe and Haystack colonies passing through. The swim-throughs are the highlight but are only safe in very calm weather – surge through a blowhole can be violent. Because the cape faces the open ocean on multiple sides, suitable days are uncommon, and most boats heading this way continue to Haystack Reef or Althorpe Island instead. Cape Spencer suits experienced divers with a boat who happen upon a rare flat day. It is a spectacular setting and a worthwhile addition to an Innes trip when conditions allow. Skippers should keep the boat well off the cliffs, as rebound swell makes the water confused close in, and divers should be ready for a live-boat pick-up rather than returning to an anchor. A torch helps in the undercuts and tunnels, where the colour of the sponges and gorgonians only shows under artificial light. Seals are a bonus rather than a certainty here, but when they appear they tend to be curious and will follow divers along the wall.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Cape Spencer is recorded as Wall in Yorke Peninsula. 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.
- 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 Cape Spencer 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 Cape Spencer 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
Western blue groper, sweep, silver drummer, old wives, magpie perch, southern blue devils, seals, sponges, gorgonians, kelp
Location
Southernmost point of Yorke Peninsula below the Cape Spencer lighthouse in Innes National Park, with vertical drop-offs, undercuts, holes and caves cut through the point in about 10 m.
Facilities nearby
Lighthouse car park (no facilities for divers); Marion Bay ramp and services.
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
marinelife.org.auRecord updated 26 Sept 2026. Source claims are being reviewed.