DSAC's Catalina 5 is a US Navy PBY-4 Catalina whose identity has narrowed to aircraft No. 4 or No. 8 of the US Navy squadron in Darwin; the same two numbers apply to the nearby Catalina 6, and which is which has not been resolved. Darwin Harbour was a major flying-boat base during the Second World War. US Navy Patrol Wing 10 PBYs were moored in the harbour when the Japanese attacked on 19 February 1942, and from 1944 the RAAF operated Catalina squadrons from the harbour on long-range minelaying and patrol missions into the Netherlands East Indies. At least three RAAF and six US Navy Catalinas were lost in the harbour, and DSAC numbers the known wrecks Catalina 1 to 6. The PBY Catalina had a 31.7 m wingspan, a 19.4 m hull and an empty weight of about 9,500 kg, so even a broken wreck covers a surprising area of seabed. According to DSAC the aircraft was bombed and strafed by Japanese aircraft during the February raids; its fuel tanks caught fire, the wings collapsed and it eventually sank. (The club's page lists the year as 1945, which conflicts with the February raid description; 1942 is the likely date.)

The wreck lies in about 12 m on a muddy bottom. Fire destroyed much of the airframe before it sank, so the site is a collapsed wing structure, engines and scattered pieces rather than a recognisable aircraft. It is dived rarely, mostly by DSAC members documenting the harbour's aircraft, and it is a site to approach in an archaeological frame of mind: hover, look, photograph and record, and leave everything as found. For a more complete-looking Catalina, A24-69 is the better choice, but divers working through the harbour's aviation sites will want to include this one. Remember that its sister wreck, Catalina 6, is under a heritage restriction with no entry, so confirm which site you are on before descending.

Boat only. The US Navy Catalina wrecks lie in the southern harbour and East Arm, where Patrol Wing 10's flying boats were moored in 1942. The closest launch is the East Arm public boat ramp near the East Arm port; from Cullen Bay or the Stokes Hill / Frances Bay ramp allow about 20-30 minutes around Stokes Hill and down the harbour.

Positions are held by DSAC and the NT Heritage Branch rather than published, so dive with someone who has the mark, drop a shot clear of the wreck and time the dive for neap high-water slack. East Arm is more sheltered from the trade winds than the outer harbour but the water is often murkier.

Tide is everything in Darwin Harbour: the spring range is 7-8 m and tidal streams run hard through the harbour, so diving is generally only possible on neap tides (range under about 3-4 m), timed to the slack at high water when clearer ocean water sits over the site. Spring tides bring strong currents and silt-laden water with near-zero visibility. The dry season (May-October) gives the most consistent conditions; the south-east trade winds can chop up exposed water in the afternoon, so mornings are best.

In the wet season (November-April) run-off from the rivers and creeks drops visibility, afternoon storms build quickly, and the harbour is in cyclone season; box jellyfish are present October-May.

Descend the shot and locate the collapsed wing and engine remains, then circle slowly through the debris keeping the shot in sight. Return to the line to ascend.

No regular commercial trips; dived by Darwin Sub Aqua Club members and occasional private groups with the mark on neap-tide days.