The message
from The Natural Philosopher contains these words:

Guess what's more predictable than the power output from a nuclear
power station? The tides.

No. They only happen twice a day. not continuosly.

In any one place (apart from some odd situations on the South coast) but
at any one time you can find tide at every stage in its cycle somewhere
round the coast.

Going down the East Coast high tide times for the first half of today we

Peterhead 00.40
River Tees 03.26
Kings Lynn 06.40
Lowestoft 09.28
Harwich 11.43

Over in the West something similar

Liverpool 11.04
Avonmouth 06.59

--
Roger Chapman