Meet the site
Seal Island, also known as Seal Rock, is a small granite outcrop in Encounter Bay about 2.7 km south-east of Victor Harbor and 3.7 km east-north-east of Rosetta Head. Wikipedia describes it as a one-hectare mound of tumbled granite boulders scoured of soil, rising 12 m, with no vegetation and, at last survey, a breeding colony of silver gulls. It has been part of West Island Conservation Park since 1979, and its waters are within Encounter Marine Park. The Marine Life Network lists 'Seal Rocks' as a boat dive to 25 m on huge granite boulders, covered with sponges, gorgonians, zoanthids, bryozoans and ascidians, with morwong, Port Jackson sharks, yellowtail and kingfish. That matches the island's geology, and the site is taken here to be the same place. The boulders create a three-dimensional landscape of gaps, overhangs and walls, and the invertebrate growth can be colourful in good light. The site requires good boating weather and is exposed to swell from the south, so it is dived only occasionally by locals with their own boats. Currents can run around the island on big tides. Despite the name, seals are not documented as resident, but they are common throughout Encounter Bay and may visit. Seal Island suits Advanced divers comfortable with boat diving in open water, looking for a deeper, less-visited granite boulder dive than the Bluff. Combine it with Granite Island or Wright Island for a varied boat day out of the Bluff ramp. Watch no-decompression limits closely if descending to the base of the boulders, and plan a gradual ascent up the granite.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Seal Island (Seal Rocks) is recorded as Island in Fleurieu Peninsula & Victor Harbor. The listed access is boat (day trip). 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.
- Planned depth
- Confirm the intended route and training requirements; the recorded maximum is not a target.
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 Seal Island (Seal Rocks) 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 Seal Island (Seal Rocks) 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
Sponges, gorgonians, zoanthids, bryozoans, ascidians, morwong, Port Jackson sharks, yellowtail, kingfish; seals (visiting)
Location
1 ha mound of tumbled granite boulders about 2.7 km south-east of Victor Harbor, within West Island Conservation Park; huge granite boulders underwater to about 25 m.
Facilities nearby
Bluff boat ramp.
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.auen.wikipedia.orgen.wikivoyage.orgRecord updated 26 Sept 2026. Source claims are being reviewed.
