I know less about tides than I realised

[fillyboy]

For yacht master theory for example you are expected to calculate tides for secondary ports where the tide is between Spring and Neap. Here you have to use interpolation to work out the tidal curve based on the difference between the reference port at High water and low water for each of the spring and Neap tides. Its all designed to be done without a calculator.

I used to struggle with that but managed to scrape a pass, never found the need to use it in the real world.

Nobody in their right mind will say, I will arrive at 3:46PM because the height of tide above chart datum (lowest astronomical tide) is exactly 2.45m and I draw 2.3M, so 15cm is plenty for me not to run aground. Good luck with that plan.

I'm no stranger to Running aground. Isn't that why God invented bilge keelers.

 

[ajohn]

Good job I didn't have a mouthful of tea.
I'd be washing the keyboard by now.

They actually measure them at various places and use various factors to predict for others accounting for several aspects, topological and etc
eg

Real-time/near real-time data display for Weymouth | National Tidal and Sea Level Facility

ntslf.org

As I said complications above the basic reason for the tides.

 

[motorbiking]

I used to struggle with that but managed to scrape a pass, never found the need to use it in the real world.



I'm no stranger to Running aground. Isn't that why God invented bilge keelers.

View attachment 283067

May as well give the hull a clean and anti-foul while its dry.

I have a spreadsheet with a readireckoner that gives all the secondary ports in the solent area based on neap mid or spring at the reference port (Portsmouth). It's good enough. But after the YM exam I promised myself no more manual tide calcs.

 

[wobs]

Has anyone mentioned that part of Cornwall actually goes up and down with the tide as well? As in the sea bed/harbour and by extension, part of the land.