Water levels differ from the public tide predictors

[landyrev]

Hey, @kevee! Thanks for a great lib.

I'm playing with tide predictions and noticed that water levels generated by neaps/tide-predictor are quite different from the ones I can find in other tide predictors.

As an example I'm comparing the Monterey, CA tidal station, 2022-08-19

Neaps results: High level at 2022-08-19T21:08:11.000Z is 0.711727... meters Low level at 2022-08-19T17:28:11.000Z is -0.0094... meters

US Harbors results: High level at 2022-08-19T00:13:00.000Z is 1.55... meters Low level at 2022-08-19T17:31:00.000Z is 0.85... meters

So, while the time is pretty correct, the water levels looks offsetted compared to public predictions.