Meet the site
Montague Island has its own Bubble Cave, one of several in NSW. McFadyen mentions it close to Pebbly Bay near the seal colony, and the Marine Life Network describes it as a 5–30 m site on the northern headland reef with an air pocket where divers' bubbles accumulate. It warns that the air in the pocket may be poor quality – it is exhaled gas, low in oxygen and high in carbon dioxide – so divers should keep regulators in their mouths.
The cave is part of the boulder and rock reef of the northern headland, where large granite blocks form overhangs and gaps. The cave walls carry sponges, sea squirts and encrusting algae, and fish such as eastern blue devilfish, bullseyes and cardinalfish shelter inside. The reef outside ranges from kelp-covered shallows to sponge-covered rock at depth, and the proximity to the seal colony means seals often join divers. Blue groper, sweep, yellowtail and red morwong are common, and grey nurse sharks aggregate on the northern side of the island in summer.
The site suits Open Water divers who stay shallow and visit the cave, with deeper options for Advanced divers. Current can run around the northern end of the island, so the operator will choose the timing. Coordinates here are approximate. Specify Montague Island when referring to it, to avoid confusion with the Black Rock Bubble Cave at Batemans Bay or the North Solitary Island site. Operators decide on the day whether the cave is diveable, depending on swell and current.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Bubble Cave (Montague Island) is recorded as Cave/Cavern in Narooma & Montague Island. 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.
- 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 Bubble Cave (Montague 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 Bubble Cave (Montague 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
Eastern blue devilfish, bullseyes, cardinalfish, blue groper, sweep, yellowtail, red morwong, fur seals, grey nurse sharks (seasonal), sponges, sea squirts, kelp
Location
Cave in the northern headland reef of Montague Island with an air pocket formed by divers' bubbles; reef from 5 to 30 m.
Facilities nearby
Narooma town wharf and marina.
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.aumichaelmcfadyenscuba.infoRecord updated 27 Sept 2026. Source claims are being reviewed.