How to complete a tidal curve

[@fulviaquaglia885]

Your explanation was simple and clear, I finally understood. Thanks for sharing !

[@Backfromthestorm]

Wicked. Useful way of knowing if it's Springs or Leaps cheers

[@8Swindon]

Perfect and EXACTLY what I needed. Thank you!

[@phdnk]

Now that skippers have access to arithmetical division machines and numerical proportion calculation have been made cheap, it is strange that calculation is taught to be performed graphically, by inflecting lines at the intersection with diagonal. Surely this technique was employed to teach barely literate captains of XIX century. But why this approach is preserved today, when everyone is free to re-scale their bell curve to particular tide heights using computational technique that is available to them.