Ocean intelligence
When conditions are right,
you'll know.
Submarius is a mobile-first app for spearos, divers, fishermen, and boaters. Real water-clarity forecasts, honest bite scores, and a verdict for every activity on the water.
Anonymous-first. Safety features permanently free. No auth wall.
Water clarity forecast
The only app that predicts how far you'll see underwater. Satellite Kd490 turbidity, river-discharge plumes, wave mixing, and post-dive reports feed a physically-grounded visibility model. Honest uncertainty, not wishful thinking.
Bite score
A 0–10 number answering "is now a good time to fish?" It combines tide, moon, solunar tables, barometric trend, and local patterns. Cuts through the noise so you get to the water at the right hour.
Safety, always free
Shark tag alerts (OCEARCH), buddy GPS sharing, SOS, and breath-hold monitoring are permanently free, no Pro gate, no paywall. Some features shouldn't cost money.
Built differently
A verdict, not a dashboard.
Every other fishing app throws numbers at you (wind, swell, tide, moon, pressure, twelve species cards) and leaves the decision to you. Submarius reads those signals and gives you one answer: GO or DON'T. Color-coded. Explainable. Tap any factor to see exactly why.
PRIME 9.0 – 10 · everything aligned, drop what you're doing and go
GOOD 7.0 – 8.9 · confidently worth the drive
FAIR 5.0 – 6.9 · mixed, check which factor is off
ROUGH below 5 · stay home, tie flies, train breath-hold
Designed for every activity
Pick your mode. The dashboard reorders itself around the signals that matter for that activity. Multi-select supported. Switch anytime.
Free to start.
Current conditions, verdict, bite score, community spots, and every safety feature are free forever. Pro unlocks 8-day forecasts, unlimited spots, premium overlays, and offline maps.