How to

Exploring Shallow Water Shoals

Inshore Sportfishing

Using charts to identify productive reefs and shoals is key to catching quality fish like reds and kingies. SAMI OMARI provides a few tips to help you make the most of these fishy hotspots.

WHAT was meant to be an early morning drive out of Sydney and north to Coffs Harbour turned out to be a late afternoon crawl through peak hour traffic. Driving through urban gridlock is a pain during the working week, a pain that compounds when you’re on holidays and itching to get out of the city. Once past the bright lights of Sydney our collective stress levels eased, although the probability of a good night’s sleep was fading with every glance at the ticking clock. Fisho editor Jim Harnwell was in the driver’s seat accompanied by Mick Fletoridis to his left with yours truly in the back seat flicking the cabin lights on and off like an annoying little kid
– we were en route for the Dave Irvine Memorial Snapper Classic and I was getting restless.  Along the way we discussed our fishing options and strategy for the trip, however I flinched a little upon realising the extent to which we were “testing” stuff out. It seemed that everything we were using was shiny and new; to the average person that would probably have been comforting but my mind stumbled somewhat at the lack of a tried and proven safety buffer. Having a brand new sounder and GPS unit on board meant that we were practically flying solo. There were no marks in the GPS so the ability to interpret a marine chart, study a sounder and decipher cryptic messages from cagey locals would mean the difference between feast and famine on the fishing front.  

Not being overly familiar with the locations we were intending to fish led to some friendly conversation being sparked up with a couple of local fishos. This targeted banter helped us to build a mental mud map of where the fish might be holding. “You wanna be heading north, mate” was the first clue. The chart showed good grounds both to the north and also to the south; however, intelligence gathered from the locals revealed the southern grounds weren’t holding fish. Whether that was due to the lie of the land and favourable currents on the northern grounds I don’t know; what I do know was the one day out of five that we headed south we caught nothing.


“There’s good structure a few miles up, it’s all good bottom through there but we’ve been seeing some good reds on a bit of reef about the size of this room that comes up to a few fathoms – I know a bloke with a tractor but you should be able to launch with your fourbie,” manifested itself as clue number two. The tractor and 4WD references indicated a beach launch. Studying the chart showed a couple of locations where the headlands and beaches provided suitable launching access. Sure enough, dotted along the coast near these locations were spot soundings that emerged from the surrounding flat bottom and rose to form what appeared to be clusters of reef. A number of the reefs which had three to five fathom changes in depth contour were earmarked for further exploration. After gleaning a few more useful tips we consulted our marine park maps and admiralty charts to develop a game plan. The following morning we launched the Fishing World Stabi Craft with all eyes turning to the chart plotter and sounder once we started approaching fishable water. A number of shallow water shoals had been noted on the chart and it was now simply a case of hitting each one, getting a sense for what the bottom looked like and moving about till we found the fish. The motor was cut well upwind after arriving at the first likely looking mark on the chart with the drift planned to take us from the deeper surrounds on the periphery to the shallows across the top of the reef. Flicking soft plastics and occie jigs around soon saw the first snapper of the day quickly fought and landed by Fisho sales manager Chris Yu, who had driven up from Sydney that morning. The next fish caught us all by surprise with Jim getting hit on the drop by a runaway steam train.  The drift had taken us over the gravel bottom adjacent to the reef proper and Jim had hooked a substantial fish that just didn’t want to stop. After an incredible series of powerful, headshaking runs a beautifully conditioned 14lb red surfaced and lay still for the net and awaiting cameras. It was a cracking fish and gave a wonderful account of itself on relatively light tackle. I followed shortly after with a nobby headed 10lb fish taken in similar shallow water country, which we’d first marked on the chart and drifted over with the sounder.

As the tide slowed, so did the snapper and we sent the Stabi further afield to investigate some islands and rocky outcrops in the distance. The swirling current and foaming white water around the northern tip of a nearby island was where we found action. The chart showed a stepped ledge, the sounder was blacked out with baitfish and every soft plastic or metal jig dropped to the bottom was set upon by schools of ravenous kingfish, hefty tailor and voracious little amberjack. Reading the chart, interpreting the underwater landscape on the sounder while constantly on the move and exploring new terrain meant that the action was never too far away. We started the trip with no marks in the GPS and ended up marking about a dozen or so locations and landing snapper up to 14lb and kings up to 25lbs – all thanks to doing a little homework and utilising the technology at hand to its full potential.


Charting the way

Paper admiralty charts and their electronic counterparts found in modern day chart plotters contain a wealth of information for the navigator and angler alike. Whilst marine charts were intended for use as a navigational tool, the bottom contours and depth readings provide useful clues for the thinking fisho.  Contour lines that are close to one another indicate a sudden change in depth. A shallow water shoal in charted territory is usually shown as a series of contours marked numerically to highlight a change in depth. As an example, if your chart shows a constant 20m contour then suddenly shows a series of two concentric circles with a 15m depth reading on the outer circle and a 10m depth reading on the inner circle, then you can probably assume that you have stumbled upon a reef that rises up from a potentially featureless 20m sandy bottom to about 10m – the closer the circles are together, the steeper the rise. The point that I’m trying to make is that a number of bommies and shallow water shoals can be readily spotted on a decent chart – take the time out to study your chart closely, make a note of the locations you find and then study them with your sounder next time you hit the water.  Your sounder will provide confirmation of the structure and will help you piece together the various depth contours and wavy lines displayed on the chart.

Sounder strategies

I think most sounders are under utilised by the masses. A sounder tells you a number of interesting points, however the key considerations when fishing shallow water shoals are the current depth, the bottom hardness, bottom shape and the presence of “stuff”  in the water column like baitfish and predators. The biggest issue when fishing shallow water shoals is spooking the fish so “sounding around” by zig-zagging over the reef under outboard power usually isn’t the best strategy.  Instead, you should use the sounder to give you vital clues during each drift. Information like where the sand stops and the reef starts to harden or the presence of baitfish are key things to look out for when fishing a reef.  As the bottom starts to harden, the bottom trace on your sounder should thicken – a harder bottom reflects the sound wave from your transducer better than a sandy bottom, which may absorb some of the sound wave; that stronger return signal typically manifests itself on your screen as a thicker bottom trace. Knowing where the reef starts and ends along with finding any interesting gutters or bottom formations is critical if you want to plan your drift to fish a reef effectively. Similarly, the presence of baitfish displays on the sounder as a cloud like mass – a really tight ball of baitfish may signal that a predator is about as baitfish tend to swim in a tight school and move in unison when under threat to confuse their attackers. If you mark scattered bait on your sounder then the predators should eventually arrive and if the bait is tightly balled then the predators are probably already there!

Fishing the drift

Before stopping the boat to commence your drift across the reef make note of wind and current. The plan is to start on the up wind or up current side of the reef to allow the boat to drift back over the structure. Stop well short of the reef, drift past and circle back around to commence another drift – remember to keep off the reef proper while travelling to avoid spooking any fish that may be swimming along a prospective drift. The aim with the first few drifts is to figure out which part of the reef is holding the fish.  

Take note of where you are having the most success and piece together a bite pattern. Generally the fish will be feeding in some pattern either off to the side of the reef on the sandy fringes, right on top of the hard stuff or in a gutter ledge across the reef.  If you find some decent action on a gravel patch adjacent to a reef then chances are that drifting across  similar locations around nearby reefs will also produce.

Practice makes perfect

Don’t fool yourself into thinking that you will figure it all out in one session – vary your approach to a few reefs, experiment with a variety of lures and, most importantly, take the time out to learn how to properly use your sounder and GPS.  Most quality units come with comprehensive instruction manuals which detail vital functions such as gain, zoom, split screen and so on. Using your sounder with the GPS plotter to mark spots will soon become second nature to anyone keen on this sort of fishing.

When you catch a fish, make a note of what you saw on your electronics and take into consideration things like the presence of baitfish or the prevalence of bites over a particular type of structure.

Utilise a marine chart to locate structure and finish the intelligence gathering  via your sounder – there are limitless fishy locations dotted up and down the coast of this great country we live in with many shallow water shoals clearly marked for all to find and fish. Time to start studying!


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