CalTopo: Backcountry map for planning with slope angle, topo and fire layers. Navionics ChartViewer: Nautical charts and sonar depth maps for boaters, online.
| CalTopo | Navionics ChartViewer | |
|---|---|---|
| Category | Hiking, Ski & Outdoor Maps | Hiking, Ski & Outdoor Maps |
| Coverage | Worldwide, best in the US | Worldwide |
| Updates | Periodically | Periodically |
| Data source | USGS, satellite imagery and many other layers | Navionics charts and community sonar logs |
| Made by | CalTopo | Navionics (Garmin) |
| Price | Free + paid plan | Free |
| Account | Free to view, account for extras | No account needed |
| On phones | Best on a computer | Phone app available |
| Map view | Flat map | Flat map |
| Visits from ColorfulMaps | 0 | 0 |
| Open map | Open map |
What you can do with CalTopo
- Topo maps with slope-angle shading
- Draw and measure routes
- Print large maps
- Many specialist layers
What you can do with Navionics ChartViewer
- Nautical charts worldwide
- Community sonar depth contours
- Marinas and points of interest
Summary based on public information. Check each map's website for current features and prices.