---
id: weather-overlays
title: Wind, Currents & Tides
category: Weather
---

![Fig 1. Wind and ocean current overlays on the chart](weather-overlays-1.jpg)

Grid overlays sample live weather and current data across the visible chart
area, each toggled independently from the **Weather** panel (opened from the
resources list):

- **Wind** — "Enable wind layer" toggle. Requires a Signal K Weather Provider
  plugin installed on the server. Freeboard samples a 5×4 grid of points across
  the current view and refreshes them shortly after you pan or zoom. Each point
  renders as a **wind barb** by default (half feather = 5 kn, full = 10 kn,
  pennant = 50 kn, staff pointing into the wind) or, with the
  **Display → Weather → "Wind indicator"** setting set to Arrow, an arrow
  pointing where the wind flows to. Either glyph always shows the sampled wind
  speed as a label. The glyph choice is shared with the wind barbs shown on
  weather-station targets — switching the Wind indicator setting changes both
  at once. The arrow glyph can be replaced with custom artwork through a symbol
  provider plugin by publishing a symbol with the well-known id
  `windIndicator-arrow`.

- **Ocean Currents** — "Enable ocean currents layer" toggle. No server plugin
  needed — Freeboard queries the Open-Meteo Marine API directly. It samples a
  denser 10×8 grid; each arrow points in the current's flow direction, is
  colour-graded from blue (slow) to red (fast), sized by speed, and labelled
  with the current's velocity in knots.

![Fig 2. The Tidal Currents section of the Weather panel, with its 24-hour time bar, and the current overlay on the chart](weather-overlays-2.jpg)

- **Tidal Currents** — appears in the Weather panel as **"Enable tidal
  currents layer"**, but only when a `signalk-tidal-currents` plugin is
  installed on the server; otherwise this option doesn't show up at all.
  Arrows are colour-graded and labelled with speed, the same as Ocean
  Currents. What sets it apart is a **24-hour time bar** underneath the
  toggle: drag it, click anywhere on it, or use the step buttons (±1h, ±6h)
  to see how currents shift through the day, with **Play** to animate
  through time and **Now** to jump back to the current moment.

Both current arrows can also be replaced with custom artwork through a symbol
provider plugin, each under its own well-known id — `oceanCurrentIndicator-arrow`
and `tidalCurrentIndicator-arrow` — so the two overlays stay distinguishable
when shown together. Because Freeboard tints these arrows to encode speed, draw
a replacement with a plain white fill; a pre-coloured glyph comes out muddy.

All three overlays refresh automatically as you pan or zoom, and can be
shown together or independently.
