Every productive fishing spot in Australia is a change in the bottom. A chart with proper depth contours lets you find those changes from the couch, then spend your fuel confirming them instead of searching.
What contour spacing means
Contour lines join points of equal depth. Where lines bunch together the bottom is steep; where they spread out it is flat.
Tight bunched lines are drop-offs and ledges — the single most reliable structure in the ocean, because current pushes bait against them.
Wide spacing is featureless sand or mud. It can still hold flathead and whiting, but it will rarely hold a school of predators.
Humps, holes and gutters
A closed contour ring shallower than its surroundings is a hump or pinnacle. These concentrate bait and hold snapper, kingfish and pearl perch on the up-current side.
A closed ring deeper than its surroundings is a hole. Holes hold mulloway, cod and flathead, especially on the bottom of the tide when surrounding flats drain.
A long narrow deep line running out to sea is a gutter or channel — the highway fish use to move on and off flats with the tide.
Working the tide against the structure
Predators sit on the down-current side of structure and ambush bait swept past. Position up-current and let your presentation come to them.
On a run-out, fish the drains and the deeper side of banks. On a run-in, move up onto the flats behind the bait.
The first hour of movement after slack water is usually the best of the cycle.
Using our chart to do it
The Fish Finder chart draws bathymetric contours, shaded depth bands and a sounding grid over Australian waters, so you can spot ledges, humps and holes before you leave the ramp.
Use the target-depth shading to highlight the exact band a species holds in, then mark the edges where that band meets structure.
Save the coordinates of every edge you find and fish them at different tide stages. Structure does not move; the fish just shift sides.
Key takeaways
- ▸Bunched contours mean steep ground and reliable fish-holding edges.
- ▸Closed shallow rings are humps; closed deep rings are holes.
- ▸Fish the down-current side of any structure.
- ▸Mark edges, then learn which tide stage fires each one.
This guide is general information only. Fishing regulations differ by state and change regularly — confirm current rules with your fisheries authority before you fish.