Anchoring in shallow water in small swell conditions.

 Just wanting to give new boaties some good info or those new to anchoring in shallower water when there is a bit of swell around.  After watching a nice plate alloy go over the falls on a double head high wave the other day on a seemingly small swell day up here in exmouth I think a little bit of knowledge of swell is a must.  No one on board and no one hurt but a big repair bill.   This guy was an experienced boater as well.    Anyone who surfs knows the two hour rule.  At least once every two hours there is going to be a wave or set which will be minimum double the size of the average swell height. Copping a six foot set on the head on a three foot day is just about a certainty when surfing up here .  So fishing or anchoring in shallower water you need to factor this in to what you are doing. Ive had some near misses and have had my tinny swamped a couple of times at local surf breaks. Luckily never overturned.   Just sitting somewhere for 10 minutes and then thinking it is ok  to anchor is not enough particularly in water depths of less than 10m  anything less than 6m and you are asking for trouble.   You need to be vigilant in keeping an eye on the swells  in shallower water and I even have a knife up the front of my boat to cut the anchor rope if need be to get out quickly. 

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Jackfrost80's picture

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Good advise and my old boy

Sat, 2020-07-25 17:25

Good advice and my old boy calls it 'the sneaker'. You watch the wily old boys at Yallingup sitting right out back waiting for it while the young crew are further in fighting over the normal sets.


If catching wrasse is cool, consider me Miles Davis

ranmar850's picture

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Oh, no. The Rogue Wave

Sat, 2020-07-25 18:49

 Beloved of lazy journalism.  yeah, he fucked up..

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Not a good sight

Sat, 2020-07-25 20:32

Thanks for putting up the pic. a good reminder of just who is the boss on the water and don't you forget it.

peterm8's picture

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The Rogue Wave

Sat, 2020-07-25 21:35

The two hour rule is a new one! I've heard of coming in through bars on "the seventh wave" and sets that follow some multiple of four, etc, etc. 20 years of driving IRBs on both sides of the country has taught me to play the hand you're dealt. Anchoring in shallow water in WA during winter is a bad idea. 


Ambition and Ability - Don't confuse them!

ranmar850's picture

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The seventh, fourth, or sets of 3 --all can apply

Sun, 2020-07-26 10:11

 My personal opinion, after making a living on the ocean for a long time, is that some places are more prone to it than others. It seems to follow how close you are to the edge of the shelf, ie, really deep water. I worked the crayboat up along  Steep Point  and  DHI for a while, and found an otherwise low swell day could turn up a period of real swell, seemingly out of the blue, for a few hours, or less, then just drop again. And this can account for some of the fatalities  along the coast north of Carnarvon, although most of these are down to sheer stupidity. And not accounting for a rising tide. 

Landbased=rising tide danger

Boatbased=falling tide danger. 

But again, most of it is just down to just not looking at it for long enough, or reading the signs. On first sight, as you arrive, the ocean may appear calm, no swell, but the signs of recent big sets will be there for the educated eye to read.  Look at surge, discolouration, spindrift, rips pulling dirty water out from the beach. Back before we had stuff like buoyweather and real swell prediction, you'd look over the side in shallow water, which was clear on the surface, and the bottom was indistinct, stirred up.  Divers know this--you can feel a swell coming a day  before it is apparent on the surface. Or you'd see a rip of dirty water heading out from a beach, with no apparent swell--things are starting to move. 

peterm8's picture

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 Yep, stopping and looking is

Sun, 2020-07-26 15:34

 Yep, stopping and looking is the way to go. 


Ambition and Ability - Don't confuse them!

carnarvonite's picture

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Counting waves

Sun, 2020-07-26 16:54

 Hezzy may back me up on this  but I never have gone with the counting waves theory, having rowed dinghies out through breakers professionally netting salmon over many season [and being snotted by getting the timing wrong] its a case of being able to see about 4 or 5 waves back to give you enough time to get to deep water.

Son was bringing a Kailis trawler, Tubridgi K, down from Exmouth to Fremantle a few years back and got really snottered out off Point Quobba in 100 foot of water, he said he could see the wave coming about 3 sets away and couldn't do anything except wear it. Punched the whole front of the wheelhouse in, flooding everything including the 240volt switchboard giving him and the co skipper big electric shocks.

timboon's picture

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 What was the story here

Mon, 2020-07-27 19:53

 What was the story here Cruzy?


Boat going over the falls? So it had already snapped the anchor rope or am I missing something here?


Where is the pic is that down grave yards or something?

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Date Joined: 08/10/13

 Anchored up in about 5m of

Mon, 2020-07-27 21:00

 Anchored up in about 5m of water at the surf break. Out going tide lots of anchor rope out. Went glassy from offshore and the boat swung around.  5 wave 4ft or double head set came in and it made it through three  that broke on it getting pulled back by the anchor. Wave 4 the anchor swung it around violently as it slid to the bottom of the wave and sucked the thing straight under and flipped upside down.  I thought he was going to move it a few times and I was going to tell him but he was sitting to far away in the line up. Sat upside down all night just off the beach before the boys flipped it in the morning which was a monumental task.

Pescatore70's picture

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 very important thread

Mon, 2020-07-27 21:13

 very important thread this.

Ive seen a number of boats anchored close almost put themselves ina world of shit because they were either too lazy to give themselves plenty rope or simply not have enough in the 1st place.


As a small boat owner myself im loathed to anchor unless i have been out there for some time and not noted any change in swell.


Always..always lift your head and look at the horizon. 

timboon's picture

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 Yeah which break Cruzy?? Bit

Mon, 2020-07-27 22:59

 Yeah which break Cruzy??


Bit of coast doesn't look familiar....

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Sounds like Burrows ! Few

Tue, 2020-07-28 05:04

Sounds like Burrows ! Few tennis copped it in that channel back in the day.

Pete F's picture

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 Just not a good place or

Tue, 2020-07-28 08:34

 Just not a good place or depth to anchor at any time... Fish those spots with two people, one casting one driving and watching the seas. Life jackets on too!





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 Heard another big plate ally

Tue, 2020-07-28 18:32

 Heard another big plate ally got flipped at false passage off tantas yesterday. Apparently a complete write off. It was very  big swell yesterday and that is somewhere you dont need to be near in a big swell it is a scary place especially on an outgoing tide. It was a surfer so probably parked at the surf break there.