Destinations: Browns Mountain/Woolnough Knoll

Browns Mountain is the local name for the undersea morass known officially as Woolnough Knoll. An extinct submerged volcano that's estimated to be 260 million years old, its twin peaks rise to about 180 metres above the sea floor from a depth of 440 to 600 metres at its base.

It’s a location where you’re going to need a large, competent boat that can handle a mix of conditions that may include punching all the way home in strong winds and big seas.

A bit of mystery surrounds how the site gained the name Brown's Mountain. The knoll was originally discovered in the 1870s, and given the name Woolnough Knoll in the 1920s in honour of pioneer Australian geologist Walter Woolnough.

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The origin of the name Browns Mountain, though, is less clear. One story, and the most plausible, is that it was named by former Sydney Game Fishing Club member Jack Paton using the nickname for his old deckhand.

The big attraction of Browns Mountain is the mix of fish species the reefs around the morass attract. This includes blue-eye, hapuka, bass groper, gemfish and mako in winter; yellow and bluefin tuna in autumn and spring; all gamefish including blue marlin in summer and autumn; broadbill swordfish at night; and big sharks all year round.

It’s so popular that during Sydney’s controversial COVID-19 lockdowns, NSW Water Police patrolled the area to catch fishers who had travelled well outside their quarantine zones to get there.

That’s quite an achievement in itself because to get there is an effort. The morass sits 42 kilometres, around 23 nautical miles, east of Sydney, just off the edge of the continental shelf, which will take the average boat around 1.5 hours to reach. The area is influenced by the East Australian Current, which moves south at anywhere between 1.0 knots in winter and up to 4.0 knots in summer, so it’s best approached from the north.

Check the speed of the current ahead of your visit, because if it is moving at 4.0 knots it is likely to be too fast for bottom-bashing.

During the week, there may only be a handful of boats heading out to the mountain, however on weekends, there are likely to be a large number of boats gathered.

The most important part of any trip out to browns Mountain is knowing the weather. While a westerly wind will help you out to the site, if it builds it’s likely to be a long, slow and rough trip back in. And if your boat is going to sink in those conditions, it will sink very quickly.

If the wind gets up unexpectedly, conditions can deteriorate fast. Be prepared to make an early call to run for home.

You’re well out of sight of land this far offshore, so being able to navigate safely and accurately – especially if your onboard electronics fails – is important. Ensure your boat’s compass is working, as it’s a great back-up. 

You will also need to carry plenty of fuel. The rule of thirds – a third of a tank out, a third of a tank back in and a third of a tank in reserve – is very important, as is the need to carry extra fuel in jerry cans. 

Why jerry cans? As we've noted before, the mountain sits inside the East Australian Current, which moves along at a fair clip. If you’re bottom-fishing you will need to keep the boat constantly in gear to hold your position, which can burn through a surprising amount of fuel – as will chasing a hooked-up fish to land it.

If the weather turns bad and you’ll need to run for home, the extra fuel is just a bit more insurance to get you there safely.

Most boats will sit north of the morass in about 400 metres of water so as they fish they drift back along the northern slope, which extends for about a mile.

So, what happens if you do get in trouble? That far out to sea, there is no mobile phone reception.

By law, once a boat is more than 2.0 nautical miles from the shore you will need to have gear such as flares and an EPIRB onboard, as well as a marine VHF radio.

A smart back-up is a satellite phone, allowing you to make contact with someone onshore, which is a vital step in how well people survive an incident offshore.

As well, the newest generations of EPIRBs and personal locator beacons can now send GPS-based location data to rescue coordinators, meaning they will know exactly where you are and then relay that to those heading out to help you.

Because Browns Mountain is a popular fishing location, using a flare to signal for help is likely to attract a few boats to come to your aid.

If you can’t make it out to Browns Mountain, each year between October and May the NSW Department of Primary Industries places fish aggregation devices at several sites around The Peak and the 9 and 12 Mile Reefs off Sydney that are much closer to home.

These FADs attract the bait fish that the larger species feed upon, which should make things as exciting as a trip out to Browns – but without the risks that an extended offshore trip will bring.

There’s also the edge of the continental shelf about 27 nautical miles offshore where gamefish such as yellowfin congregate.

Never been out to Browns before, but would like to give it a crack someday? Consider going out there on a professional charter boat, or tag along with someone who’s been there before to see what is involved.

Even when you’re confident enough to make the trip as a skipper for the first time, tee up a buddy boat that you can travel and fish with, and who will have your back if things start to go pear-shaped.

Browns Mountain (34.02.588S, 151.39.417E) is roughly 22nm east off the Sydney coast, 19nm off Botany Bay heads, and 23nm off Port Jackson.

You’ll need to check the weather, your boat and its safety gear carefully to ensure all are within the scope of what is a significant offshore excursion.

Aim slightly north of the morass as you head out to account for the East Australian Current, which flows south at anywhere between 1.0 knots in winter and up to 4.0 knots in summer.

Carry extra fuel even if you’re confident you have enough to make a round trip.