[Right Wing Professor]

Carefully note the precise lag between the tide rising compared to the overhead orbital position of our Moon. That lag helps indicate the propagation speed of Gravity.

So you think that two points with the same longitude always have high tide at the same time?

[Southack]

"So you think that two points with the same longitude always have high tide at the same time?"

Absolutely not.

[thulldud]

It has more to do with the propagation speed of water waves than it does gravity. Also, you got to take into account local geography and especially resonant cavities (Bay of Fundy, anyone?).