Repositories list

• slackwater-ios

  Public
  Slackwater for iPhone: offline tide and current predictions

  iosios-apptides+ 2

  iosios-apptidescurrentsharmonics

  Swift

  •

  GNU General Public License v3.0

  •00 forks in openwatersio/slackwater-ios•44 stars in openwatersio/slackwater-ios•6666 issues in openwatersio/slackwater-ios•33 pull requests in openwatersio/slackwater-ios•Updated Oct 27, 2026Oct 27, 2026

• slackwater-database

  Public
  Station database for tide and current predictions

  tidetidescurrents+ 5

  tidetidescurrentstidal-datatide-forecastsconstituentstidal-currentsharmonic-constituents

  HTML

  •

  Other

  •88 forks in openwatersio/slackwater-database•2727 stars in openwatersio/slackwater-database•3838 issues in openwatersio/slackwater-database•22 pull requests in openwatersio/slackwater-database•Updated Oct 27, 2026Oct 27, 2026

• openwaters.io

  Public
  The website

  Astro

  •00 forks in openwatersio/openwaters.io•00 stars in openwatersio/openwaters.io•1515 issues in openwatersio/openwaters.io•77 pull requests in openwatersio/openwaters.io•Updated Oct 27, 2026Oct 27, 2026

• noaa-water-level-research

  Public
  Reproducible prospective evaluation of NOAA water-level forecasts, with original receipts and explicit accuracy criteria.

  Python

  •

  MIT License

  •00 forks in openwatersio/noaa-water-level-research•00 stars in openwatersio/noaa-water-level-research•33 issues in openwatersio/noaa-water-level-research•00 pull requests in openwatersio/noaa-water-level-research•Updated Oct 27, 2026Oct 27, 2026

• status

  Public
  Status page and uptime history for Open Waters services

  Markdown

  •

  MIT License

  •00 forks in openwatersio/status•00 stars in openwatersio/status•11 issue in openwatersio/status•00 pull requests in openwatersio/status•Updated Oct 27, 2026Oct 27, 2026

• slackwater.xyz

  Public
  Landing page for Slackwater — offline tide and current predictions

  iostidescurrents+ 3

  iostidescurrentscloudflare-workerstanstack-startmarine-navigation

  TypeScript

  •00 forks in openwatersio/slackwater.xyz•00 stars in openwatersio/slackwater.xyz•2525 issues in openwatersio/slackwater.xyz•33 pull requests in openwatersio/slackwater.xyz•Updated Oct 27, 2026Oct 27, 2026

• slackwater

  Public
  Tide and current prediction engine for TypeScript and Swift

  swifttypescripttide+ 14

  swifttypescripttidegistidestidalcurrentsharmonicsmarinetidalcycles+ 7

  TypeScript

  •

  MIT License

  •1212 forks in openwatersio/slackwater•3737 stars in openwatersio/slackwater•3434 issues in openwatersio/slackwater•1515 pull requests in openwatersio/slackwater•Updated Oct 26, 2026Oct 26, 2026

• crowd-depth

  Public

  openwatersio/crowd-depth’s past year of commit activity
  Collect and share depth data from your marine vessel with crowd-sourced bathymetry programs.

  noaasonarmarine+ 6

  noaasonarmarineihocrowdsourcesignalkbathymetrymarine-datacrowdsourced

  Python

  •

  MIT License

  •33 forks in openwatersio/crowd-depth•88 stars in openwatersio/crowd-depth•1212 issues in openwatersio/crowd-depth•44 pull requests in openwatersio/crowd-depth•Updated Oct 26, 2026Oct 26, 2026

• seamap

  Public
  A nautical-themed map with depths, seamarks, and hazards

  vector-tilesopenstreetmaposm+ 7

  vector-tilesopenstreetmaposmnauticalmvtnautical-chartsopenseamapmaplibrepmtilesseamarks

  TypeScript

  •

  GNU General Public License v3.0

  •00 forks in openwatersio/seamap•1515 stars in openwatersio/seamap•2323 issues in openwatersio/seamap•55 pull requests in openwatersio/seamap•Updated Oct 26, 2026Oct 26, 2026

• almanac

  Public
  Offline sun & moon engine — positions, rise/set, moon phase, eclipses. Twin Swift + TypeScript ports, one fixture corpus.

  swifttypescriptastronomy+ 9

  swifttypescriptastronomymoonephemerissuntwilightmoon-phasemarinecelestial-navigation+ 2

  Swift

  •

  MIT License

  •00 forks in openwatersio/almanac•33 stars in openwatersio/almanac•33 issues in openwatersio/almanac•00 pull requests in openwatersio/almanac•Updated Oct 26, 2026Oct 26, 2026

• aiscast

  Public
  aiscast, the Open Waters AIS network: aisstream.io-compatible streams from open feeds and volunteer receivers

  marineaissignalk+ 5

  marineaissignalkmarinetrafficnmea0183signalk-pluginaishubaisstream

  Go

  •

  MIT License

  •11 fork in openwatersio/aiscast•88 stars in openwatersio/aiscast•2020 issues in openwatersio/aiscast•66 pull requests in openwatersio/aiscast•Updated Oct 26, 2026Oct 26, 2026

• seascape

  Public
  A map of the seafloor built from global open bathymetry.

  vector-tilesnoaamapbox+ 11

  vector-tilesnoaamapboxmbtilesterrariumdemmvtnautical-chartsbathymetrymarine-data+ 4

  Python

  •

  Other

  •00 forks in openwatersio/seascape•2121 stars in openwatersio/seascape•5757 issues in openwatersio/seascape•1212 pull requests in openwatersio/seascape•Updated Oct 26, 2026Oct 26, 2026

• chs-current-validation

  Public
  Year-round validation results for Slackwater's fitted CHS current gates

  TypeScript

  •

  MIT License

  •00 forks in openwatersio/chs-current-validation•00 stars in openwatersio/chs-current-validation•00 issues in openwatersio/chs-current-validation•00 pull requests in openwatersio/chs-current-validation•Updated Oct 26, 2026Oct 26, 2026

• .github

  Public
  Open Waters org profile & community health files

  Shell

  •00 forks in openwatersio/.github•00 stars in openwatersio/.github•33 issues in openwatersio/.github•22 pull requests in openwatersio/.github•Updated Oct 25, 2026Oct 25, 2026

• maritime-zones

  Public
  Offline where-am-I and distance-to-territory lookups over the Marine Regions maritime boundaries, as FlatGeobuf tiles

  offlinesailingflatgeobuf+ 4

  offlinesailingflatgeobufeezmaritime-boundariesterritorial-seamarine-regions

  TypeScript

  •

  Other

  •00 forks in openwatersio/maritime-zones•22 stars in openwatersio/maritime-zones•44 issues in openwatersio/maritime-zones•00 pull requests in openwatersio/maritime-zones•Updated Oct 24, 2026Oct 24, 2026

• enc-tiles

  Public
  Tools to produce vector tiles from Electronic Navigational Charts

  mapboxmbtilesenc+ 9

  mapboxmbtilesencnauticalmarinenautical-chartsihos57ecdismaplibre+ 2

  TypeScript

  •

  Apache License 2.0

  •66 forks in openwatersio/enc-tiles•1414 stars in openwatersio/enc-tiles•66 issues in openwatersio/enc-tiles•66 pull requests in openwatersio/enc-tiles•Updated Oct 24, 2026Oct 24, 2026

• chart-catalog

  Public
  Catalog of freely redistributable electronic navigational charts, pre-baked as vector tiles

  Shell

  •

  MIT License

  •00 forks in openwatersio/chart-catalog•00 stars in openwatersio/chart-catalog•11 issue in openwatersio/chart-catalog•00 pull requests in openwatersio/chart-catalog•Updated Oct 24, 2026Oct 24, 2026

• tile-fonts

  Public
  SDF glyph stacks for the Open Waters map styles, served from tiles.openwaters.io/fonts

  Shell

  •

  SIL Open Font License 1.1

  •00 forks in openwatersio/tile-fonts•00 stars in openwatersio/tile-fonts•11 issue in openwatersio/tile-fonts•00 pull requests in openwatersio/tile-fonts•Updated Oct 24, 2026Oct 24, 2026

• tippecanoe

  Public
  Docker image with tippecanoe and tile-join, published to ghcr.io

  Dockerfile

  •

  BSD 2-Clause "Simplified" License

  •00 forks in openwatersio/tippecanoe•11 star in openwatersio/tippecanoe•11 issue in openwatersio/tippecanoe•00 pull requests in openwatersio/tippecanoe•Updated Oct 24, 2026Oct 24, 2026

• xtide

  Public
  Docker image with xtide, xttpd, and tcd-utils.

  Dockerfile

  •00 forks in openwatersio/xtide•00 stars in openwatersio/xtide•11 issue in openwatersio/xtide•00 pull requests in openwatersio/xtide•Updated Oct 24, 2026Oct 24, 2026

• OpenWaters

  Public
  An experiment in building modern marine charts. Currently alpha and not to be use for navigation.

  TypeScript

  •

  GNU General Public License v3.0

  •11 fork in openwatersio/OpenWaters•1515 stars in openwatersio/OpenWaters•3838 issues in openwatersio/OpenWaters•66 pull requests in openwatersio/OpenWaters•Updated Oct 24, 2026Oct 24, 2026

• signalk-tides

  Public
  SignalK plugin for offline tide predictions at the vessel's position, powered by Slackwater

  tidessailingmarine+ 4

  tidessailingmarinesignalkmarine-datatidesandcurrentssignalk-plugin

  TypeScript

  •

  Apache License 2.0

  •1212 forks in openwatersio/signalk-tides•55 stars in openwatersio/signalk-tides•77 issues in openwatersio/signalk-tides•88 pull requests in openwatersio/signalk-tides•Updated Oct 24, 2026Oct 24, 2026

• coordinate-format

  Public
  A simple and flexible TypeScript library to format decimal latitude/longitude coordinates into degrees/minutes/seconds (DMS) and other coordinate formats.

  TypeScript

  •

  MIT License

  •00 forks in openwatersio/coordinate-format•00 stars in openwatersio/coordinate-format•00 issues in openwatersio/coordinate-format•00 pull requests in openwatersio/coordinate-format•Updated Oct 24, 2026Oct 24, 2026

• homebrew-tap

  Public
  Homebrew formulae for Slackwater and other Open Waters tools

  Ruby

  •00 forks in openwatersio/homebrew-tap•00 stars in openwatersio/homebrew-tap•00 issues in openwatersio/homebrew-tap•00 pull requests in openwatersio/homebrew-tap•Updated Oct 10, 2026Oct 10, 2026

• docker-shipfeeder

  Public
  AIS feeder for ShipXplorer, VesselFinder, MarineTraffic, etc. based on AIS-Catcher. Multi-architecture (amd64, armhf, arm64)

  Shell

  •

  GNU General Public License v3.0

  •1010 forks in openwatersio/docker-shipfeeder•00 stars in openwatersio/docker-shipfeeder•00 issues in openwatersio/docker-shipfeeder•00 pull requests in openwatersio/docker-shipfeeder•Updated Oct 7, 2026Oct 7, 2026

• noaa-current-stations

  Public archive
  NOAA CO-OPS tidal-current station data: extractor, schema, and the API's undocumented behaviour

  JavaScript

  •

  MIT License

  •00 forks in openwatersio/noaa-current-stations•00 stars in openwatersio/noaa-current-stations•00 issues in openwatersio/noaa-current-stations•00 pull requests in openwatersio/noaa-current-stations•Updated Oct 1, 2026Oct 1, 2026

• chs-constituents

  Public archive
  Fit harmonic constituents for CHS current stations from IWLS predictions, with in-process validation and confidence tiering

  chstidescurrents+ 4

  chstidescurrentssignalkiwlstidal-predictionharmonic-constituents

  TypeScript

  •

  Other

  •00 forks in openwatersio/chs-constituents•00 stars in openwatersio/chs-constituents•00 issues in openwatersio/chs-constituents•22 pull requests in openwatersio/chs-constituents•Updated Sep 30, 2026Sep 30, 2026

• slackwater-android

  Public
  Native Android app for offline tide and current predictions.

  GNU General Public License v3.0

  •00 forks in openwatersio/slackwater-android•00 stars in openwatersio/slackwater-android•1616 issues in openwatersio/slackwater-android•00 pull requests in openwatersio/slackwater-android•Updated Sep 28, 2026Sep 28, 2026

• AisLive_pi

  Public
  OpenCPN plugin to receive AIS from online sources

  C++

  •

  GNU General Public License v3.0

  •11 fork in openwatersio/AisLive_pi•11 star in openwatersio/AisLive_pi•00 issues in openwatersio/AisLive_pi•00 pull requests in openwatersio/AisLive_pi•Updated Sep 24, 2026Sep 24, 2026

• station-metadata

  Public archive
  Provider-neutral tide and current station identity, metadata, search aliases, and corrected positions

  geocodingnoaachs+ 4

  geocodingnoaachsstationstidescurrentscorrections

  JavaScript

  •

  MIT License

  •00 forks in openwatersio/station-metadata•11 star in openwatersio/station-metadata•00 issues in openwatersio/station-metadata•00 pull requests in openwatersio/station-metadata•Updated Sep 22, 2026Sep 22, 2026