

The HMAS J1 sits on the seabed off Victoria as one of Australia's few diveable submarine wrecks, resting at 35 to 36 metres in deep diving territory. The hull is colonised by yellow zoanthid corals and attracts various fish, but the wreck demands respect before you descend. Strong currents run across the site, and the overhead environment inside creates genuine entanglement and navigation risks. Visibility runs 10 to 15 metres, which is workable, but cold water and depth mean your bottom time is short and decompression planning is non-negotiable. Boat charter with a guided tour is the sensible way to approach this one.
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Plan your dive around slack water to manage the strong current, and treat this as a strict no-deco dive given the depth and cold water will burn through your bottom time faster than you expect. A dive computer with a conservative algorithm and a surface marker buoy are essential.
Access is via dive charter boats, typically departing from Portsea or Queenscliff. The boat trip is approximately 55 minutes. The wreck is located about 4.5 kilometres east of Point Lonsdale.
This is a challenging dive due to depth and potential strong currents. Penetration of the wreck is considered very hazardous due to tight spaces and the risk of silt-out. Redundant air sources are considered mandatory for penetration. The dive has claimed lives in the past.
Depth
35-36m
Visibility
10-20m
Skill Level
Advanced
Entry
Boat
Boat required
Water Temp
14-20°C
Current
Mild
Typical Dive
40 min
Best Time
Year-round
Yes, HMAS J1 Submarine in Melbourne is a boat-access-only dive site. You will need to book with a local dive operator or charter a boat to reach it.
HMAS J1 Submarine in Melbourne requires advanced diving skills. Expect deeper depths, currents, or challenging conditions that are not suitable for newly certified divers.
Diving at HMAS J1 Submarine in Melbourne requires the following certifications: Open Water, Wreck, Deep, Nitrox. Always dive within your training limits.
A 7mm wetsuit or semi-dry is recommended for diving at HMAS J1 Submarine in Melbourne. Water temperatures range from 14°C to 20°C.
HMAS J1 Submarine in Melbourne is home to yellow zoanthid corals and various fish. Marine life sightings vary by season and conditions.
The best months to visit HMAS J1 Submarine in Melbourne are January, February, March, April, May, June, July, August, September, October, November, and December. Conditions outside these months can still be good but are less predictable.
HMAS J1 Submarine in Melbourne has depths ranging from 35 metres to 36 metres.
A typical dive at HMAS J1 Submarine in Melbourne lasts approximately 40 minutes. Actual dive time depends on depth, air consumption, and conditions.
HMAS J1 Submarine in Melbourne typically has mild currents that most divers can handle comfortably.
Visibility at HMAS J1 Submarine in Melbourne typically ranges from 10 metres to 20 metres. Conditions vary with weather, tides, and seasons.