Orca is designed to make boating effortless, whether you're a seasoned boater or a new owner. A key part of that experience is Orca's visual chart interface, which uses standardised colours and symbols that closely mimic official paper charts. This article walks you through what those symbols and colours mean, so you can navigate with confidence.
Viewing and Understanding Chart Symbols Using Orca
To get more information about a chart feature whilst using the app, follow these steps:
Long-press the feature icon on the map.
Tap "View Info" in the menu that pops up.
This will display detailed information about the selected feature, including its type, and key identifiers such as colours or flashes.
Chart Colours, Markers & Symbols
Below is an overview of the different symbols you can find in the app:
Chart Colours
Grey – Land: Avoid unless you're on foot.
Blue (Dark to Light) – Water: Darker shades indicate deeper waters. Affected by your Depth Threshold setting.
Green – Intertidal Zones: Dry at low tide, submerged at high tide.
Magenta – Warnings, Notices, Restrictions.
Markers & Buoys
🔴 Red – Port-hand: Keep to your left when entering from sea. (IALA A: Applies to most of the world)
🟢 Green – Starboard-hand: Keep to your right when entering from sea. (IALA A: Applies to most of the world)
🟡 Yellow – Special Areas: Scientific zones, caution areas, etc.
🟠 Orange – Local Zones: Often no-wake or regulation-specific areas.
🔵 Blue – Facilities: Moorings, marina services.
🔴 Red – Starboard-hand: Keep to your right when entering from sea. (IALA B: America, Japan, Korea, and the Philippines)
🟢 Green – Port-hand: Keep to your left when entering from sea. (IALA B: America, Japan, Korea, and the Philippines)
Orca icons
The icons above are used in Orca. For reference of their meaning:
Chart Symbols
Anchorage – Safe place to anchor
Marina / Docks – Harbors and docking facilities
Tidal / Current Flow – Arrows show direction and flow.
Lighthouse / Beacon – A light source for nighttime navigation.
Ferry Lanes / Traffic Zones – Areas with vessel traffic separation.
Rock / Submerged Danger – Exercise caution.
Beacons & Buoys
Cardinal (N, E, S, W) – Mark dangers and indicate safe water direction.
Lateral (Port, Starboard, Channel) – Show navigational routes and limits.
Safe Water & Isolated Danger – Special buoys for open water or hazards.
Shapes: Can, Cone, Sphere, Spar, Pillar – Indicate buoy type and meaning.
Structures
Towers, Pylons, Cairns, Poles – Man-made aids to navigation.
Dolphins, Piles, Mooring Buoys – Indicate mooring or hazard structures.
Special Features
Seaplane Areas, Marine Farms, Wind Turbines – Marked for safety and avoidance.
Fog Signals, Floodlights, Vertical Clearance Warnings – Alert mariners to key risks or limits.
Unsurveyed Areas
Unsurveyed areas within areas where we have chart coverage are shown with blue and white stripes (see screenshot below)
