Navigation & Chart Overlays

Puts sea marks, harbours, anchorages, electronic charts, buoyage, wrecks and regulated areas onto the chart — the core cartographic information you need to prepare and run a coastal passage.

Where to find it

Map › floating Overlays button (top-left of the map) › Navigation tab (anchor icon).

The Overlays panel is a draggable button sitting on the map. Click it to open the panel, then select the Navigation tab in the tab bar at the top. A counter shows how many overlays are active in the category.

Hierarchy

Overlays (floating map panel)
└── Navigation (tab, anchor icon)
    ├── SeaMarks          (OpenSeaMap)
    ├── Harbours          (Ports & anchorages, OpenStreetMap)
    ├── Sea-Seek          (sailing guides)
    ├── ActiveCaptain     (Garmin community POIs)
    ├── Chart Bounds      (offline chart coverage)
    ├── ENC Charts        (S-57 / S-52 vector)
    ├── Buoyage           (SHOM, France)
    ├── Wrecks            (SHOM, France EEZ)
    ├── Regulation        (SHOM navigation regulation)
    ├── Ports Infra.      (SHOM port infrastructure)
    ├── Marine Areas      (Marine Protected Areas, OFB)
    └── Réglem. nav.      (prefectoral regulations, PING/SHOM)

The Navigation category

What it's for

These twelve overlays lay nautical data onto the chart for conning the vessel: sea marks and buoyage, harbours and anchorages, vector electronic charts, wrecks and obstructions, and the various regulated areas (anchoring bans, marine protected areas, prefectoral orders). Most are detailed datasets that only appear at large scale: you have to zoom in to make them show.

How to use it

1. Open the Overlays panel on the map.
2. Click the Navigation tab (anchor icon).
3. Click an overlay to turn it on: the button lights up and the layer appears on the chart.
4. If the overlay needs a minimum zoom level, a yellow reminder (info icon) shows under the active button. Zoom into the area until the markers load.
5. Click the button again to turn the overlay off.

Available overlays

Options & settings

• Overlay button: one click toggles it on/off. A lit button takes an accent colour; off, it stays grey.
• Zoom reminder (yellow info): under each active overlay that has a minimum zoom, a message reminds you of the level to reach (e.g. "Zoom in (level 9+) to see nautical marks", "Zoom ≥ 11"). It disappears once the data loads.
• Tab counter: the small number on the Navigation tab shows how many of its overlays are active.
• Presets: the bar at the top of the panel (bookmark icon) lets you save the active overlay combo under a name (+ button) and reload it later. Handy to store a "coastal approach" or "offshore" set.

Tips & limits

• Zoom in first: most of these overlays load nothing until you are close enough. If a layer looks empty, check the yellow reminder and zoom into the area.
• SHOM data = France: Buoyage, Wrecks, Regulation, Ports Infra. and Réglem. nav. cover French waters (and the EEZ). Outside France these layers stay empty.
• Marine Areas (AMP): French marine protected areas, visible from level 7 — earlier than the other SHOM layers.
• ENC Charts: official vector charts with S-52 symbology; what shows depends on the charts available in your area.
• Chart Bounds: shows the footprint of your imported offline charts (coverage rectangles), with no minimum zoom — useful to confirm what you have loaded before an offline passage.
• Sea-Seek / ActiveCaptain: two complementary catalogues of points of interest (ports, anchorages, hazards). Click a marker to open its detail card.
• Réglem. nav. (PING): 5,233 prefectoral-order zones (anchoring, diving, fishing, navigation). Always check the order in force before anchoring or diving.
• Several overlays can be active at once, but stacking dense sources (buoyage + wrecks + regulation) can clutter the chart: enable only what you need.

See also

• Weather overlays
• Current overlays
• Safety overlays