Tidal stream chartlets and diamonds

[chris-s]

Why do all tidal diamonds and some chartlets have HW-6 to HW+6 whilst others only HW-5 to HW+6 ? Even for the same area varies between publisher.

 

[MoodySabre]

The hour of HW is HW-30 to HW+30. The hour of LW is LW-30 to LW +30. Some /\/\/\/\/\/\/\/\/\/\ explanations put the HW or LW at the top of each /\ others put it in the trough.

I think.

 

[James_Calvert]

Why do all tidal diamonds and some chartlets have HW-6 to HW+6 whilst others only HW-5 to HW+6 ? Even for the same area varies between publisher.

If you look at the +6 and -6 details they are often very similar if not the same.
And the time calculated from the previous HW +6 and the next HW-6 is in the order of a quarter hour difference.

So in practice missing out the HW -6 details doesn't matter much.