All through the dry you look at the Darwin tide chart and the low low is in the middle of the night. Then one week in late August it's at lunchtime and the flats are back online. I go through the tide chart every year and I've been telling people on the course for years that it switches. This year we counted it, every tide in the 2026 table.
The low low
Most days up here have two lows, and on the springs one of them is a fair bit lower than the other. That's the low low, and it's the one that matters, because that's the tide that empties the drains right out and gets the bait moving, jelly prawns, mullet, everything, and it's the one that kicks you off the flat if you've stayed too long.
From April through to August, on the spring tides, the low low is at night. From September through to February it's during the day. The switch is the last week of August, give or take a few days, and it goes back the other way around March, towards the end of the wet.
Go through the springs month by month and it's an absolute pattern. April to August, one spring day out of ten at most has its lower low during the day, and some months it's none. September to February it's nine out of ten, and some months every one of them. In May and June there isn't one low tide during the day under 2 m at Darwin. In October there are 19.
"Barra don't bite in the dry"
Every year someone tells me the barra shut down in the dry season. How can you say that when the tide isn't running out far enough during the day for them to get working? What's actually happened is the water you want is in the dark, so the drains aren't emptying while you're out there and the flats aren't draining, and the spots that fire on a 2 m low at 11 in the morning in October go quiet at 11 in the morning in June.
Why it switches comes down to where the moon sits in the sky. Through the year the full and new moons swing from riding high over Darwin to sitting low in the north, and that's what makes one of the day's two tides bigger than the other and decides which one it is.
September to March
That's when we fish the flats on the low. Spring tides, a fast run-out in the morning, and on the back of the moon a low under 2.5 m around lunchtime or a bit later. That's when the drains empty right out and it gets everything happening, and the barra have to move. So you fish the flats as they drain, then the drains as they get to the end of the run-out, and then the rocky points right on the bottom of the tide when everything else has gone quiet. Bynoe, the flats in the harbour, the coastal creeks. Bynoe runs about half an hour earlier than Darwin, so take that off.
The back of the moon is my favourite. A day or two after the full or new moon you're on the biggest tides of the month, and from September on that means the biggest lows during the day as well. Those days get booked out first every year.
Sight casting on the neaps is a totally different story. That's about clarity and the slow part of the tide. This is about the springs, the days the flat drains.
April to August
Through those middle months, on the springs, the low during the day is the higher of the two, so you change where you fish. You're looking for the deeper banks that drain off quicker, the rock bars at the end of the runoff, the river mouths on the neaps when the water's clean, and the bluewater when the sea goes flat. It's a different time of year. The dry is when we plan the fly and sight-casting trips, because that's when you get the clean water.
Tide first, then wind
None of this guarantees a bite. What it tells you is when the water will be where you want it. Up here, with tides this size, it's tide first, then wind and water clarity, and the moon bite times third.
Go and look at your own chart. Find the week it switches this year and when it goes back at the end of the wet, and see what your flats are doing in between. If you've got a flat that only fires on the daytime low, tell me which one. I'm a bit of a tide chart nerd, I want to know.
The tides cheat sheet is a free download if you want the whole year on one page.
Rather learn it on the water?
This is what the safaris are for.
Three to eight days, one guide, and the same water you have been reading about. Everyone fishes with Watty.