Submarius
Ocean intelligence for Miami.
Miami sits at the convergence of three distinct ocean environments: the shallow flats of Biscayne Bay, the shipwreck-dotted Atlantic just past Government Cut, and the Gulf Stream edge minutes offshore where sailfish and mahi stream through year-round. Submarius reads all three, weights them per activity, and gives you a verdict. Free, no signup.
Choose your activity
Outer reef tracts, ledges off Haulover, and bluewater runs from the inlets. Water-clarity forecast + tide + moon in one verdict.
Artificial reefs, deep wrecks, and natural reef tract. Vis forecast, surface conditions, and current context per dive site.
Bonefish on the flats, tarpon in Government Cut, sailfish and mahi offshore. Bite score combines tide, moon, solunar, and pressure trend.
How Miami's ocean actually behaves
Three zones run through almost every conditions question for Miami:
- Biscayne Bay and the flats. Shallow, tide-driven, and sensitive to rainfall and sediment pushed off the shoreline. Tide stage governs vis and fish behavior more than anywhere else in the region.
- The inlet zone (Government Cut, Haulover). High-current passes where bay water and ocean water exchange. Bonito, tarpon, snook, and jacks concentrate here on moving tides.
- The outer reef and Gulf Stream edge. Typically clearer water, stable temperatures, and pelagic traffic when the Stream pushes close to shore. Ledges at 60–120 ft hold the full reef-fish complex plus structure-oriented amberjack and grouper.
Submarius reads conditions at sub-kilometer resolution, so a forecast for your Biscayne Bay spot isn't the same as one for Government Cut or the outer reef, and it shouldn't be.
Water clarity in Miami
Miami's clarity can swing by 30+ feet from one day to the next. Strong incoming tides can lift sediment off the Biscayne flats and spread it across the inshore reef. Sustained easterly winds stir up the outer reef. Heavy rain upstream pushes plume water through the inlets. None of that shows up on a wave-height app.
Our clarity forecast starts from each spot's typical clarity for the time of year, built from in water measurements and satellite ocean color, then subtracts wave stirring, river and runoff plumes, and tide movement. Every estimate shows a low to high range and its data sources. An honest range is better than a confident but wrong number.
How the clarity forecast works →Safety in Miami's water
Miami is shark country year-round: bulls, blacktips, lemons, hammerheads, and the occasional tiger. Submarius surfaces OCEARCH tagged-shark positions and community sightings on the map, with push notifications for sightings in your active tiles. Buddy GPS sharing and SOS are one tap away. All safety features are permanently free, regardless of subscription tier.
Common questions
Miami's inshore waters (Biscayne Bay, the Intracoastal) behave very differently from the outer reef and Gulf Stream edge. The bay is shallow, tide-driven, and turbid after rain or strong incoming tides pushing sediment off the flats. The outer reef is clearer and more stable, driven by Gulf Stream influence and swell mixing. Submarius reads clarity at sub kilometer resolution from satellite ocean color and in water measurements, so the forecast reflects the tile you're actually diving, not a city wide average.
Spearfishing, scuba diving, and saltwater fishing have dedicated Miami location pages with live conditions and activity-tuned verdicts. Surfing is less of a Miami activity (the coast is generally flat), so no dedicated surf page here. Boating users get the same marine forecast plus structure overlays for known reefs and wrecks.
Yes. Shark tag alerts (OCEARCH), community shark sightings, buddy GPS sharing, and SOS are permanently free for every user, everywhere Submarius runs, never gated behind Pro. This is a structural commitment, not a trial offer.