I thought I understood.

[Graham_Wright]

Why two tides a day?
The deeper I research, the more confused I become.
The latest investigation was into the "Admiralty Manual of Navigation".
Quite at odds with internet derived information.
The Admiralty version is via static gravitational computations.
The internet arrives at a dynamic solution (which, to me, makes more sense).
What do the forum experts believe?

 

[Stemar]

If you're looking for an expert, better not look at me, but...

AIUI, almost everywhere has two tides because the actual influence of the sun and moon is quite small; most of the work is done by the momentum of the water sloshing backwards and forwards. A bit like pushing a swing, it only takes a tiny push at the right time to build up the momentum.

 

[S04]

That's interesting as I've looked in my copy of the Admiralty Manual of Navigation (2008) and can see no reference to "static gravitational computations". Which version are you using?

 

[rogerthebodger]

This is how I understand why terre are 2 high and 2 low tides a day.

 

[oldbloke]

It's amazing how difficult it is to get an correct answer. The clip above is just wrong with its earth bulge and the assertion that the far side tide is lower than the near side. My understanding which may be wrong , but at least it is simple, is that the moon doesn't go round the earth but they both go round a central point, which is inside the earth but nearer the moon rather than at its centre. So the surface of the earth furthest from the moon is furthest from the centre of gravity therefore gravity is less there therefore the second bulge/ high tide

 

[S04]

.................. the moon doesn't go round the earth but they both go round a central point, which is inside the earth but nearer the moon rather than at its centre. ................................................

Yes
Source is Admiralty Manual of Navigation Vol1

 

[Graham_Wright]

That's interesting as I've looked in my copy of the Admiralty Manual of Navigation (2008) and can see no reference to "static gravitational computations". Which version are you using?

1964!
It also references black starboard hand buoys!

 

[Graham_Wright]

I thought and believe that centrifugal/centripetal forces were players. That I can understand.