Submarius: Dive & Spearfishing

One glance at waves, water clarity, wind, and tides. Scout reefs on the map. Share spots with friends. Works offline.

Submarius reads the ocean and reports everything you need to know to make a decision. Dive weather, bite forecast, and water clarity forecast for spearfishing, diving, fishing, and boating — built for people who are tired of stitching together four apps to decide if today is worth the drive.

A VERDICT, NOT A DASHBOARD Every factor — wind, swell, tide, moon, pressure, water temp, water clarity — goes into a single 0–10 verdict you can read in two seconds. Tap any factor to see the numbers and the reasoning. No black-box "AI" — every input is transparent.

THE FIRST HONEST WATER CLARITY FORECAST No other major app has this. Submarius blends satellite turbidity (NOAA CoastWatch Kd490), USGS river-plume detection, wave-mixing physics, and community post-dive reports into an honest Secchi-depth estimate with explicit uncertainty. Grounded in Lee et al. 2015 (R²=0.96). When we don't know, we say so.

EIGHT ACTIVITY MODES Spearfishing, freediving, scuba, rod-and-reel fishing, boating, sailing, surfing, kayak/SUP. Each mode reweights the verdict around what actually matters for that activity — clarity and tide for spearos, swell period and wind for surfers, bite windows for anglers, small-craft advisories for boaters.

BITE SCORE WITH TRANSPARENT FACTORS Dive forecast with water clarity, bite score, swell, tide, and moon — every factor explained. Tide stage, moon phase, solunar windows, barometric trend, wind, and water temperature — combined into a 0–10 score, factor by factor. No secret formula. If we score a day a 3, you'll know exactly why.

MAP THAT'S ACTUALLY USEFUL Self-hosted bathymetry + sea-surface temperature + animated weather radar + wind particle flow + reef and wreck structure overlays. Finds drop-offs, temp breaks, and shelter without dragging you to another app.

LIVE GPS TRACKS Record your dive or fishing trip as a live blue track on the map. Useful for retracing drift, marking productive zones, or just remembering the line you swam.

SAFETY, ALWAYS FREE Shark-tag alerts (OCEARCH), community shark sightings, SOS, and buddy GPS sharing are permanently free for every user, every tier. No paywall, no trial — by design.

SPOT PRIVACY, BY DEFAULT Your spots stay your spots. GPS-fuzzed to ~1 km on anything public; precise location never leaves your device unless you explicitly share it. Post-dive clarity reports ship with H3-fuzzed coordinates only — we can't give away where you dive because we never see it.

ANONYMOUS-FIRST Current conditions, 2-day forecast, basic bite score, and every safety feature work without an account. Sign up when you want to save spots or post catches.

SUBMARIUS PRO Pro unlocks the 8-day forecast, premium map overlays, offline maps, unlimited saved spots, advanced bite score layers, full water-clarity horizons, and catch history export. $12.99/month or $99/year with a 7-day free trial. Limited $149 lifetime tier for the first 1,000 founders.

Subscriptions bill through your Apple ID and renew automatically unless cancelled at least 24 hours before the end of the current period. Manage in Settings → Apple ID → Subscriptions.

Privacy: https://submarius.com/privacy Terms: https://submarius.com/terms