Browns Mountain Fishing: Gemfish & Kingfish off Sydney

Browns Mountain is one of Sydney's best-known deep-water offshore fishing grounds, and two trips in July 2019 showed exactly why anglers keep making the long run. On the first trip, gemfish were biting almost immediately in about 420 metres before a sudden increase in current ended the session. Two days later, the crew returned, caught kingfish on 100 g jigs at The Peak on the way out, then found the gemfish at Browns again.

Andrew first wrote about these trips in 2019. The gear has changed since then, but the fishing lessons remain just as useful: what appeared on the sounder, how the deep-water bite unfolded, how quickly the current changed, and why 100 g jigs worked well for the kingfish at The Peak.

Where Is Browns Mountain?

Browns Mountain is a deep-water seamount on the edge of the continental slope offshore from Sydney. It is approximately 41 km east of Kurnell, about 19 nautical miles from the entrance to Botany Bay and about 23 nautical miles from Port Jackson. NSW fisheries material has long associated the area with deep-water species including gemfish, while detailed bathymetric mapping shows Browns rising from the surrounding continental slope.

The reference point above comes from a 2023 Browns Mountain and Woolnough Knoll destination guide. It is also consistent with older published marks. A WGS84 fishing mark reported by a Sydney angler in 2007 was 34° 02.200′ S, 151° 39.500′ E, about 730 metres away, while a 2016 Browns Mountain fact file used 34° 02′ 00″ S, 151° 39′ 20″ E, about 1.1 km away. Those marks all identify the same Browns Mountain area; the small differences reflect different points on a substantial, double-peaked offshore structure rather than Browns being one pin-sized fishing spot.

How to Get to Browns Mountain by Boat

There is no single departure route because boats approach Browns from Port Jackson, Botany Bay, Broken Bay and other Sydney ramps. The practical method is to enter the reference coordinate into a correctly configured chartplotter, confirm that it falls on the Browns Mountain structure shown on your current chart, and then build a safe route from your own departure point.

1. Check the coordinate format before entering it. Many chartplotters use degrees and decimal minutes, so enter 34° 02.588′ S, 151° 39.417′ E exactly in that format. Do not enter 02.588 as decimal degrees.
2. Plan from the heads you will actually use. Browns is roughly 19 nautical miles from Botany Bay heads and 23 nautical miles from Port Jackson. A trip from Brooklyn or Broken Bay is considerably longer; the first trip in this article covered more than 100 nautical miles for the day.
3. Allow for the East Australian Current. The current commonly sets south across this area and can change substantially. Watch course over ground, speed over ground and fuel use during the run rather than assuming the boat will track directly to the waypoint on a fixed compass heading.
4. Use the chart and sounder once you arrive. The coordinate gets you to Browns Mountain, but the exact fishing position depends on the depth, current direction, target species and the part of the structure you want to work. Detailed bathymetry shows a double peak with a trough between them.
5. Calculate the complete return range before leaving. Include the run out, trolling or repositioning around Browns, the trip home and a sensible fuel reserve. Conditions at Browns can be very different from those closer to shore.

A high-resolution C-MAP view of Browns Mountain is useful for understanding why one coordinate cannot represent every productive part of the feature. Use the reference waypoint to get to the area, then use current bathymetry, the sounder and the day's current to choose the actual drift or trolling line.

On these July 2019 trips Andrew was fishing in approximately 420 metres of water. That depth is what makes Browns a completely different proposition from Sydney's inshore reefs. Every drop puts hundreds of metres of line into the water, so current, drift, braid diameter, sinker weight and retrieve time matter enormously. Conditions that look manageable inshore can become a serious problem that far offshore.

Trip One: Sydney to Browns Mountain

Saturday 20 July 2019 started before sunrise at Brooklyn. Andrew had been invited aboard James Taylor's Blackwatch 30 for a run wide of Sydney. With the gear loaded, they headed out with a north-westerly tailwind.

The first stop was Twelve Mile Reef. Around eight boats were already fishing, but the scene did not inspire confidence. Andrew's first impression was that the reef looked quiet, and James' Garmin sounder backed that up: the bottom appeared almost bare.

Rather than spend the morning dropping into empty-looking water, they continued to Browns. The sounder picture there was far more encouraging.

Gemfish in 420 Metres

For the Browns session Andrew used a Daiwa Tanacom 750 outfit with 50 lb braid and a baited deep-water rig. The relatively sensitive rod tip made subtle bites easier to see, while the thinner braid presented less area for the deep-water current to push against. At approximately 420 metres, reducing drag on the line made a noticeable difference.

The rig went down to roughly 420 metres. As soon as the sinker reached bottom, Andrew lifted it about five metres to clear the extremely rough structure. Almost immediately the rod tip gave the familiar tap-tap-tap of a bite. The crew had hooked up within about 30 seconds of reaching the sea floor.

The gemfish were smaller than Andrew remembered from previous seasons, but they were there in numbers. The crew was hooking fish on every drop.

When the Current Suddenly Changes

About an hour into the session, one of the crew noticed a line of breaking water approaching from a few hundred metres away. At a place where more than 400 metres of line may be below the boat, that was bad news.

The drift jumped from approximately 0.5 knots to 2.5 knots. That five-fold increase was enough to end the Browns session. Strong current creates more drag on the line, pushes the rig away from the boat and makes maintaining controlled contact with the bottom increasingly difficult.

The crew pulled the pin rather than trying to force the fishing. They trolled much of the way home and the GPS track showed just how substantial the day had been: more than 100 nautical miles travelled.

That sudden change is probably the most important non-fishing lesson in the whole report. Browns Mountain is serious offshore water. Forecast, fuel range, vessel capability, communications and the willingness to turn around matter more than squeezing in one extra drop.

Trip Two: Kingfish at The Peak

Two days later, on Monday 22 July, Andrew headed back offshore with experienced fishing mate Greg and younger crew Oscar and Xavier. This time the first target was The Peak.

The Peak is not one single neat reef. Andrew describes it as a collection of bumps and productive patches spread across the sea floor. His approach was to move between known areas while watching the sounder, then drop only when bait or kingfish gave the crew a reason to fish.

For another 2019 session at The Peak, including its reference coordinates and the day blue 200 g jigs became the standout lure, read Gemfish & Kingfish off Sydney: Browns Mountain and The Peak.

That sounder-led approach paid off, and Xavier caught his first kingfish on a jig.

Why 100g Jigs Worked at The Peak

The original article says the crew's 100 g jigs worked well on the 40-80 metre reef fishing. That is useful real-world evidence, but it should not be read as a rule that 100 g is always correct for that depth.

Jig weight depends on more than metres. Current speed, wind, boat drift, braid diameter, jig shape and the depth where fish are actually holding all influence whether a lure can reach and stay in the strike zone. The best practical starting point is to use the lightest jig that will reach the fish reliably and remain under useful control. If the line angle keeps opening and the jig sweeps away from the marks before it gets there, step up in weight.

The jig shown in the original 2019 report was an earlier Downrigger Shop design. Our current 100 g knife jig was introduced in 2022, but the practical lesson remains the same: the 100 g weight class can be extremely effective for Sydney reef and wreck jigging when the current and conditions suit it.

Back to Browns Mountain

The kings were not thick enough for Andrew to spend the whole morning at The Peak, particularly with stronger wind forecast later in the day. The crew continued to Browns.

The current was already running hard, but the gemfish were there again. The Browns sounder picture was good enough that when Andrew later posted it to Facebook, anglers asked what transducer and settings he was using.

Sounder settings vary between units, transducers and conditions. The important thing is to learn how your own sounder displays bottom structure and fish. Choose a colour palette and sensitivity level that make targets easy to distinguish, then compare what appears on the screen with what happens when your rig reaches depth.

Oscar soon had his first gemfish.

But the sea was already building in the background. After only a couple of drops, the crew headed home. For the second time in three days, Browns had produced fish quickly but conditions determined how long they could safely stay.

What These Two Browns Mountain Trips Still Teach

Browns Mountain Fishing FAQs

Where is Browns Mountain fishing ground?

Browns Mountain is a deep-water seamount offshore, directly east of Sydney. It is a serious blue-water run rather than an inshore reef. NSW fisheries material has referred to Browns Mountain in connection with game-fish tagging and deep-water species, including gemfish.

How deep is Browns Mountain?

Depth varies around the structure and with the exact area being fished. In these two 2019 Downrigger Shop trips, Andrew describes fishing at approximately 420 metres. That is why current, line drag, sinker weight and the time required to retrieve a rig are such important parts of the story.

What are the Browns Mountain fishing coordinates?

A useful Browns Mountain reference point is 34° 02.588′ S, 151° 39.417′ E in degrees and decimal minutes, or -34.043133, 151.656950 in decimal degrees. This puts you on the Browns Mountain structure. Once there, use your chart, sounder, target depth and the direction of the current to choose the exact area and drift you want to fish.

What fish are caught at Browns Mountain?

Gemfish are the focus of these two winter 2019 reports. Browns is also known as a deep-water fishing area for other species, while pelagic fish can be encountered offshore depending on season and conditions. The nearby stops in this story - Twelve Mile Reef and The Peak - were separate, shallower fishing grounds.

Can I use a 100g jig at Browns Mountain?

The 100 g jigs in this article were used for kingfish at The Peak, not for the 420 m gemfish fishing at Browns. A 100 g jig can be excellent on suitable Sydney reefs and wrecks, but it should not be treated as the Browns Mountain setup simply because both locations appear in the same trip report.

What is the NSW bag limit for gemfish?

As of August 2026, NSW lists gemfish within a combined bag limit of five deep-sea fish, with a maximum of two gemfish per person and a boat trip limit of ten gemfish. Regulations can change, so confirm the current NSW fishing rules before heading out.

Continue the Sydney Jigging Guides

If you're targeting kingfish rather than fishing deep at Browns, start with How to Jig for Kingfish in Australia. For the question anglers ask most often, see What Weight Jig Should I Use?. You can also read the related 2019 case study, Gemfish & Kingfish off Sydney: Browns Mountain and The Peak.

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