Turn official chart data into confident decisions
SeaVectors portrays official Electronic Navigational Chart data as an interactive vector chart. Instead of looking at a flat picture, you can zoom without losing sharpness, control which features appear, and tap charted objects to inspect their attributes.
The portrayal follows familiar S‑52 conventions used with professional electronic charts. Learning a few core ideas—depth areas, contours, soundings, navigation aids, hazards, and your safety settings—will make every other SeaVectors feature more useful.
Want to explore with waters you already know?
- Download SeaVectors on the App Store
- Get SeaVectors on Google Play
- Or open the lightweight web chart for a quick chart preview.
ENC, S‑57, and S‑52 in plain language
- ENC — an official Electronic Navigational Chart made from individual vector features rather than one scanned image.
- S‑57 — the data standard used to encode chart features and their attributes.
- S‑52 — the portrayal conventions used to draw those features with consistent colors and symbols.
This matters because a buoy, light, contour, wreck, restricted area, or depth area is a real object that SeaVectors can identify and display according to context—not merely a colored mark in a picture.
Read depth information first
Depth areas
Water is divided into charted depth bands. Shallow and drying areas are emphasized while deeper water is differentiated by the selected portrayal and safety settings. Treat the colors as an aid to scanning the chart, not as a declaration that an entire colored area is safe for your vessel.
Depth contours
Depth contours (DEPCNT) connect positions of equal charted depth. They help reveal channels, shoals, banks, and the shape of the seabed.
Soundings
Soundings (SOUNDG) are individual charted depth values. Confirm the selected unit—meters or feet—before interpreting them.
Charted depths are normally referenced to the chart's vertical datum. Actual water depth changes with tide, atmospheric conditions, waves, river flow, survey age, seabed change, and other local effects. A sounding is not the same thing as a live depth-sounder reading beneath your boat.
Drying areas
Areas that uncover at low water may be portrayed differently from water that remains submerged. Inspect the feature information and relevant tide conditions rather than judging from color alone.
Configure safety depth for your vessel
Your Safety depth setting helps SeaVectors emphasize a relevant contour and distinguish depth areas around a threshold you choose.
A useful starting point considers:
- Your vessel's maximum draft
- Desired under-keel clearance
- Expected squat, heel, and wave action
- Tide and water-level uncertainty
- Survey quality and local seabed change
Do not simply enter the vessel's draft and assume everything beyond the highlighted contour is safe. The available ENC contours may not exactly match your chosen value, and isolated shoals or hazards can exist inside otherwise deeper water.
Configure units and safety values under Settings → Map Settings. See 17 · Settings Reference for the related options.
Recognize the main chart features
| Feature | What to look for |
|---|---|
| Land and coastline | Shoreline, islands, foreshore, and charted structures |
| Navigation aids | Buoys, beacons, lights, sectors, ranges, and characteristics |
| Hazards | Rocks, wrecks, obstructions, foul ground, and shallow areas |
| Restricted areas | Charted boundaries and associated restrictions or cautions |
| Traffic features | Traffic schemes, fairways, channels, recommended tracks, and separation zones |
| Submarine features | Cables, pipelines, and associated caution areas |
| Depth information | Areas, contours, soundings, dredged areas, and drying features |
Tap a charted object instead of guessing. SeaVectors opens an information sheet containing the attributes available in the ENC, such as its name, category, characteristics, restrictions, or reported depth.
See lights, sectors, buoys, and beacons as navigation aids—not generic map icons
SeaVectors portrays charted buoys, beacons, and navigation lights from their ENC attributes using familiar S‑52 conventions. Their shapes and colors carry meaning, helping you connect what appears on the screen with the aids you expect to see on the water.
- Buoys and beacons retain their charted symbol types so lateral, cardinal, special-purpose, and other supported aids remain distinguishable.
- Light colors are shown from the ENC record, including red, green, white, and yellow.
- Sector lights use their charted sector limits and colors to show the bearings over which each light is intended to be seen.
- Directional and fixed light beams help identify leading or alignment guidance where that information is present in the chart data.
- Nominal range is taken from the charted light attributes rather than assigned as a generic visual effect.
In the native SeaVectors app, a light's portrayal becomes more prominent as your vessel enters its charted nominal range. This lets distant lights remain part of the wider chart while drawing your attention toward the aids that are becoming relevant nearby—particularly useful during harbor approaches and night passages.
Tap a light to review its available characteristics before relying on it. Nominal range is not guaranteed visibility: weather, haze, background lighting, observer height, the condition of the aid, and other atmospheric effects can change when a real light becomes visible.
This is one of the clearest benefits of an interactive ENC chart. Instead of showing every light as the same static icon, SeaVectors uses charted attributes and your navigation context to make the portrayal more useful at the helm. Install SeaVectors and try it in a harbor you know during the 30-day full-access trial.
Choose the right chart style
| Style | Best use |
|---|---|
| Nautical | Primary ENC reading and daytime planning |
| Night | Lower-glare viewing in a dim wheelhouse or cockpit |
| Satellite | Additional visual context for shorelines, marinas, and land features |
| Relief | Coastal terrain and topographic context |
| City Details | Roads and place context around developed waterfronts |
The ENC features remain the authoritative navigation layer. Satellite imagery can be old, offset, obscured, or captured at a different tide and must not be used by itself to determine safe water. At night, use the night style and reduce screen brightness enough to protect your vision.
Move around without losing orientation
- Pan — drag with one finger.
- Zoom — pinch or double-tap. More ENC detail appears as you move closer.
- Rotate — twist with two fingers.
- Tilt — move two fingers vertically for a perspective view.
- Locate and follow — use the location control to center and track the vessel.
- Return north-up — tap the compass to reset orientation.
When assessing a confined area, periodically return to north-up and zoom out. It is easy to lose the wider traffic, hazard, and escape-route context while working close in.
A five-minute chart-reading exercise
- Open a harbor or passage you know well.
- Confirm the displayed depth unit and set a considered safety depth.
- Identify the main channel using contours, soundings, navigation aids, and traffic features.
- Find one shallow area, hazard, light, and restricted area; tap each and read its details.
- Switch between Nautical and Night styles, then briefly use Satellite for shoreline context.
- Zoom out and identify a safe alternative or turning area if the intended route becomes unavailable.
This exercise turns chart symbols into something connected to real local knowledge and is a better trial of SeaVectors than simply panning at random.
Control clutter without hiding what matters
If the chart feels crowded, adjust sounding size and visibility or use the layers control. Avoid removing safety-relevant features merely to make the chart look cleaner.
Continue with 03 · Map Layers & Detail Control to learn the quick groups and detailed S‑57 layer controls.
Troubleshooting
- The chart looks empty — zoom in and confirm the required layers are enabled.
- Soundings are difficult to read — check the depth unit, sounding size, bold-text option, and visibility timing.
- The depth shading seems wrong for your boat — review safety depth and units; remember that shading is based on chart data and configured thresholds, not live measured clearance.
- A symbol is unfamiliar — tap it for available ENC attributes and consult the applicable official chart-symbol reference when needed.
- No chart appears — confirm internet access, coverage, and that you are looking at a supported US or Canada West Coast area.
Build confidence with your own waters
Install SeaVectors and start the 30-day full-access trial, then repeat the exercise above in a harbor you know. Familiar geography makes it much easier to understand what the chart is communicating and how SeaVectors can support your decisions.
Navigation safety
No display setting can determine safe water by itself. Use current official information, appropriate scale, tide and weather data, your vessel's actual draft and handling, live observations, and a proper lookout. SeaVectors aids navigation; it does not replace competent chart interpretation or prudent seamanship.