Submarius
Updated October 14, 2026
Navionics vs Submarius.
These apps aren't really competitors. They solve different problems. Navionics (now owned by Garmin) is a nautical charts platform: depth contours, navigation aids, tide and current vectors, and offline coastal maps. Submarius is a conditions app: wind, swell, tides, radar and a bite score rolled into a 0 to 10 verdict for your spot.
| Feature | Submarius | Navionics |
|---|---|---|
| Detailed nautical charts | NOAA charts, US only (Pro) | ✓ its core product |
| Depth contours | ✓ bathymetry layer (Pro) | ✓ SonarChart™ |
| Offline chart download | Depth map and reefs and wrecks, no charts (Pro) | ✓ |
| Turn by turn marine routing | N/A | ✓ |
| Dock to dock navigation | N/A | ✓ |
| Tide and current predictions | ✓ tides; regional drift current in dive modes | ✓ raw data |
| Single number verdict (0 to 10) | ✓ | N/A |
| Bite score | ✓ | N/A |
| 8 day marine forecast | ✓ (Pro) | Basic overlay |
| Visibility estimate for divers | ✓ with a confidence figure, in dive modes | N/A |
| Shark awareness card (Spearfishing mode) | ✓ free | N/A |
| Community spots | N/A, your spots stay private | Community edits (charts) |
| Pricing | US: $12.99 a month, $99 a year, or $149 once | Paid subscription, price varies by region |
Who should use Navionics?
If your boat doesn't have a dedicated chartplotter, or if you want a backup for the one you have, Navionics is the gold standard on mobile. The SonarChart™ depth contours are genuinely crowdsourced and updated frequently. Dock to dock routing accounts for chart depths and low bridges. Offline charts for a trip to the Bahamas or the Keys are just worth it.
Captains, cruisers, and anyone navigating unfamiliar water, this is your tool.
Who should use Submarius?
Submarius answers a different question: should I take the boat out today? Not how do I get from here to there safely? (That's Navionics' domain.) If your decision each weekend is "is the bite on?" or "is vis good enough to dive?" or "should I wait until Sunday morning?", that's where Submarius shines.
Specifically:
- Spearos and divers get current, swell, tide and a visibility estimate with a confidence figure in the dive modes.
- Anglers get a 0 to 10 bite score that weighs light, moonlight, how fast the tide is moving, water temperature extremes, and wind and waves, so they don't have to combine it all in their heads.
- Weekend warriors get an 8 day outlook with Pro, so they can pick the best day of the week instead of guessing.
- Anyone gets Safety Watch (a float plan with SOS) and the shark awareness card in Spearfishing mode, with no Pro gate. Safety Watch needs a free account.
The complementary setup.
A setup that works: check Submarius in Fishing mode the morning of the trip ("verdict is GOOD, best window 6 to 9 AM, bite score 8.1"), or the night before with Pro to see tomorrow's rating. Open Navionics when you're actually underway ("which channel, what depth, any chart hazards").
Looking for a Navionics alternative for charts?
Submarius isn't a chart replacement. The map opens on satellite imagery, and Pro adds official NOAA nautical charts for US waters as a layer, plus a bathymetry layer. The NOAA chart layer needs a connection and isn't saved in offline areas. That's useful along the US coast, but it doesn't match Navionics' SonarChart detail. If you specifically need that level of chart fidelity, use Navionics.
Evidence and related reading.
Try the conditions side.
Wind, swell, tides and radar for your spot, and a 0 to 10 verdict before you leave the dock.