Meet the site
Lewis Island is one of the Thorny Passage islands south of Port Lincoln, and the Marine Life Society describes it as principally a seal colony dive in about 10 m, with nice bommies off the south-west tip and very colourful marine life. It adds that visibility is moderately poor and currents very strong in the deeper locations. Seals from the colony – Australian sea lions and fur seals occur in this area – often join divers in the shallows, swooping and blowing bubbles. The bommies off the south-west tip are covered in sponges, ascidians and algae, with sweep, old wives, magpie perch, blue devils and western blue groper among them. Currents through Thorny Passage are the main complication: the deeper areas should be dived at slack water, with a tender following divers' SMBs. Visibility tends to be lower here than at the outer islands. Lewis Island suits experienced divers with a boat who want a seal encounter without travelling to the Neptunes or paying for a tour, and it combines with Taylors Island and Memory Cove for a Thorny Passage day. Seal encounters are most rewarding when divers settle quietly on the bottom in the shallows rather than chasing the animals, and summer and autumn, when young seals are active, are usually the liveliest times. Because visibility can be limited, stay close to your buddy and the reef, and use a surface marker so the boat can track you in the current. As with all seal colonies in South Australia, keep dives compact and be alert for white sharks.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Lewis Island is recorded as Island in Eyre 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.
- 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 Lewis Island 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 Lewis Island 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
Seals and sea lions, sweep, old wives, magpie perch, southern blue devils, western blue groper, sponges, ascidians
Location
Island in Thorny Passage principally dived for its seal colony, with bommies off the south-west tip and colourful marine life in about 10 m; very strong currents in deeper spots.
Facilities nearby
Port Lincoln ramps 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.