rtide

Introduction

rtide is an R package to calculate tide heights based on tide station harmonics.

It includes the harmonics data for 1293 US stations.

Installation

To install the latest release from CRAN

install.packages("rtide")

To install the developmental version from GitHub

# install.packages("pak")
pak::pak("millerlp/rtide")

Utilisation

library(tibble)
library(rtide)
#> rtide is not suitable for navigation

data <- rtide::tide_height(
  "Monterey Harbor",
  from = as.Date("2016-07-13"), to = as.Date("2016-07-15"),
  minutes = 10L, tz = "America/Los_Angeles"
)

print(data)
#> # A tibble: 432 × 3
#>    Station                               DateTime            TideHeight
#>    <chr>                                 <dttm>                   <dbl>
#>  1 Monterey, Monterey Harbor, California 2016-07-13 00:00:00      0.523
#>  2 Monterey, Monterey Harbor, California 2016-07-13 00:10:00      0.505
#>  3 Monterey, Monterey Harbor, California 2016-07-13 00:20:00      0.489
#>  4 Monterey, Monterey Harbor, California 2016-07-13 00:30:00      0.476
#>  5 Monterey, Monterey Harbor, California 2016-07-13 00:40:00      0.465
#>  6 Monterey, Monterey Harbor, California 2016-07-13 00:50:00      0.457
#>  7 Monterey, Monterey Harbor, California 2016-07-13 01:00:00      0.452
#>  8 Monterey, Monterey Harbor, California 2016-07-13 01:10:00      0.449
#>  9 Monterey, Monterey Harbor, California 2016-07-13 01:20:00      0.449
#> 10 Monterey, Monterey Harbor, California 2016-07-13 01:30:00      0.451
#> # ℹ 422 more rows

library(ggplot2)
library(scales)

ggplot(data = data, aes(x = DateTime, y = TideHeight)) +
  geom_line() +
  scale_x_datetime(
    name = "Date",
    labels = date_format("%d %b %Y", tz = "America/Los_Angeles")
  ) +
  scale_y_continuous(name = "Tide Height (m)") +
  ggtitle("Monterey Harbour")

Shiny

Tide heights can be also obtained using rtide through a shiny interface developed by Seb Dalgarno.

Contribution

Please report any issues.

Pull requests are always welcome.

Inspiration

The harmonics data was converted from https://github.com/millerlp/rtide/blob/main/data-raw/harmonics-dwf-20251228-free.tar.xz, NOAA web site data processed by David Flater for XTide. The code to calculate tide heights from the harmonics is based on XTide.

Tide prediction updates

The harmonic constituent data for the various tide stations are updated yearly by the XTide maintainer. The rtide package originally used a harmonic data base from 2015. An updated harmonic constituent database file from 2025-12-28 has been incorporated into rtide as of v0.0.12.9000 (August 2026), which adds many new tide stations, as well as slightly changing the harmonic constituent values for many stations. As a result, tide height predictions produced with earlier versions of the rtide package (v0.0.12 and earlier) may produce slightly different values than the predictions generated by the new harmonic data base. Those differences may typically only amount to a centimeter or less.