Tide Times

[Rob Gosford]

anyone familiar with the topography of the Central Coast NSW around Gosford ?

am try to work out why the dead LOW-tide times around Gosford differ

on the Bureau of Meteorology's website (BOM) - Tidal Predictions - it gives the following information for dead LOW-tide for this Sunday 30th July as follows - http://www.bom.gov.au/australia/tides/

Patonga - 7:24 am
Ettalong - 7:56 am
Gosford - 9:47 am

why is there a 2 hour difference between Gosford's tide time to that of Patonga/Ettalong ?

as the crow flies - Ettalong is roughly 7 klms east of Patonga, with Gosford about 10klms north of Ettalong.

would it have something to do with the speed/length of drainage EAST towards the ocean - from high to low tides - in Brisbane water (Gosford) and Broken Bay (Patonga) ?

thanks

[north-north-west]

I'm not familiar with the area, but if water has to pass through a restriction (ie mouth of a bay) the tide times can be affected considerably.
Slack water at The Rip, for instance, is generally halfway between slack water times at the top of Port Phillip Bay. That's an extreme example, but it gives you an idea.

[Rob Gosford]

you can use Google Earth/Maps to view the area.

uHaaaaaaaa ! thanks north-north-west, that is very plausible ! a RESTRICTION in the water flow. Of course !

Patonga drains straight out into Broken Bay/The Ocean while Ettalong a bit east of Patonga, has a very slight 'restriction' to overcome to drain into Broken Bay/The Ocean............hence the delay of 30 minutes compared to Patonga.

AND, Gosford waterfront area - Brisbane Water - drains 10 klms south into Ettalong......THEN out to sea. During Gosford's drainage, the water (dropping to low tide) goes thru some very tight restrictions before it reaches Ettalong and then out to sea...........hence slower drainage time and LATER low tide time ? Makes sense.........

Gosford's drainage to low tide, goes thru the tight restrictions of Pelican Island/Saratoga, picking up the water from Kincumber/Davistown from the east and water from Woy Woy Bay to the west. THEN taking all of THAT to Ettalong via the tight restriction under the Rip Bridge !

hence a later low tide time of 2 hours at Gosford compared to Patonga/Ettalong, EVEN THO the 3 locations are 'relatively' close to each other in the same area.

good one north-north-west. Thanks !

Last edited by Rob Gosford on Fri 28 Jul, 2017 11:13 am, edited 1 time in total.

[GPSGuided]

Can imagine the current at the choke point.

[Rob Gosford]

Can imagine the current at the choke point.

from 45 seconds onwards..........
https://www.youtube.com/watch?v=JdGzgrYDNdw

[GPSGuided]

Beaut!

[Rob Gosford]

Beaut!

yes very informative and well done video.
Am sure I saw 'Hoges' there labouring away.......

those were the days in the 60s and 70s mate, when we used to BUILD things in this country. Not today !

[GPSGuided]

...those were the days in the 60s and 70s mate, when we used to BUILD things in this country. Not today !

Well, don't be too pessimistic. There may have been a slow down in recent decades but it's happening again here in Sydney. The amount of residential/commercial building works, public infrastructure works (M4 widening/WestConnex) amongst many others, we are 'building' like crazy. Can definitely see it and feel it whilst driving in the city. From what I hear, builder and those in related fields are being poached for high income.

Don't worry, be happy!

[Rob Gosford]

good call GPSGuided.........
I was thinking more of building dams to harness water instead of it running out to sea. Direct it to the dry farmers at Woop Woop !

ahhhhh yes, NATION building.......the cast of Utopia would be so PROUD

[GPSGuided]

Dam building is no longer cool now. Putting in a water current power generator at the Spit may be pretty cool ...