Bus Stop Reef takes its name from its most unusual ingredient: three concrete bus shelters. It was built at a time when artificial reefs were assembled from whatever durable scrap was available, and it has grown into one of the more productive fish structures in the field.

The pontoons are the dominant feature: big steel boxes that rise off the sand and provide overhangs and shade. The bus shelters, lying at odd angles, and the tyre bundles create smaller crevices, while the small steel boat adds a recognisable wreck element. After three decades underwater everything is coated in sponges, soft corals, sea whips, hydroids and oysters, and the site has the look of a small natural reef.

Golden snapper and saddletail snapper school over the pontoons, black jewfish sit in the shade, and trevally, queenfish and mackerel hunt baitfish above. The tyre piles are worth checking for lobster and small reef fish.

Because the elements are spread over the bottom rather than stacked, it is easy to lose orientation in poor visibility – keep the pontoons as the anchor point. Bus Stop Reef suits advanced divers with good buoyancy and navigation skills and anyone interested in how improvised artificial reefs mature over time. It is a good second dive after Marchart 3.

Fenton Patches lies about 17 nautical miles (roughly 31 km) north-west of Darwin in open water beyond the harbour mouth, so it is a boat-only site. Club and charter boats usually launch from the Cullen Bay ramp and marina (Marina Boulevard, Larrakeyah – ample trailer parking) or from Dinah Beach / Sadgroves Creek ramps inside the harbour, then run out past East Point and across Beagle Gulf. In a fast 6–7 m trailer boat allow roughly an hour each way in trade-wind chop; slower in a southeasterly above 15 knots.

There are no public moorings: the site is found on GPS and sounder, and a shot line or grapnel is dropped on the structure. Private boats need a competent skipper who can work the tide and keep a boat cover on the surface while divers are down.

Fenton Patches is open water in Beagle Gulf with no shelter. Dive it only on neap tides and time the dive for slack water (typically a window of 30–60 minutes around the turn; Darwin's tidal range reaches 7–8 m on springs and currents at Fenton run hard outside slack). The dry season (May–October) brings the south-east trades: mornings are usually calm, but a 15–20 knot south-easterly by late morning makes the run back uncomfortable, so plan an early start.

The build-up (October–December) brings glassy days but storms in the afternoon; the wet season (December–April) brings north-westerly monsoon winds, heavy run-off that cuts visibility, cyclone risk (November–April) and box jellyfish in the water. Visibility is best after several days of neaps and no rain.

Descend the shot to the pontoons, which are the tallest element, and use them as the reference point. Tour the pontoons, then work outward to the bus shelters, tyre piles and the small steel boat at 23–25 m, keeping the pontoons in sight or running a reel. Look into shaded gaps for cod.

Return to the shot before slack ends.

No daily operator. Darwin Sub Aqua Club (DSAC) runs member boat dives to Fenton Patches on suitable neap-tide weekends in the dry season; Dive Darwin (learntodivedarwin.com.au) and Western Blue Dive Charters offer outer-harbour/offshore wreck trips on demand when tides and weather line up. Otherwise private boat only.