The marine forecast for Sarasota and Venice comes from the National Weather Service office in Ruskin, which covers the Gulf from Bonita Beach to the Suwannee River out to 60 nautical miles. It's issued at least four times a day. Sarasota has one quirk that catches people out, so start there.
There's no forecast just for Sarasota Bay
Tampa Bay has a zone of its own. Sarasota Bay doesn't. The zones you need are:
- GMZ853, coastal waters from Englewood to Tarpon Springs out 20 nautical miles. This covers the beaches, the passes, the nearshore reefs and, in practice, Sarasota Bay. Each period includes a line for "bay and inland waters", such as light chop or choppy, and that's your bay forecast.
- GMZ873, waters from Englewood to Tarpon Springs from 20 to 60 nautical miles. Offshore.
- GMZ057, the National Hurricane Center's offshore forecast for the northeast Gulf, for anything past 60 nautical miles.
Two zones to know about but not to confuse with yours: GMZ830 is Tampa Bay, not Sarasota Bay (though it does take in Palma Sola Bay and the bottom of Anna Maria Sound), and GMZ856 covers the coast south of Englewood, if you're heading toward Boca Grande. The synopsis (GMZ800) at the top of the forecast explains the big picture, such as an approaching front or building high pressure, and it's worth reading first.
The zone list links each forecast, and the full text has every zone on one page.
What the numbers mean
Seas are forecast as significant wave height: the average of the highest third of the waves. The forecast itself warns that the highest waves may now and then be twice that, so "seas 2 to 3 feet" can still throw a rare 5- or 6-footer.
"Occasionally to" gives you the bigger sets, as in "Seas 5 to 7 feet, occasionally to 9 feet." Plan for that number.
Wave detail breaks the seas into separate wave trains with a direction, a height and a period, such as "South 4 feet at 6 seconds." The period is the time between waves. Short-period seas are steep and close together and much rougher than the height suggests; a longer period means gentler rollers.
Chop describes the bay: smooth, light chop, a moderate chop, choppy, rough. Smooth and light chop are easy going in a bay boat; by choppy you're in for a wet ride.
Thunderstorms. Every zone ends with a reminder that winds and seas are higher in and near storms. Summer afternoons in particular can turn quickly.
Advisories and cautions
- Small Craft Advisory. In the Weather Service's Southern Region, which includes Florida, an advisory goes out for average winds of 20 knots or more, or seas of 7 feet or more, lasting two hours or longer.
- Small craft should exercise caution. Used for the first forecast period when conditions are just below that: winds of 15 to 20 knots, or 6-foot seas.
Neither is a law, but both are written for exactly the kind of boat most of us launch at a ramp.
Check what's actually happening
The forecast is a prediction. These tell you what's happening now:
- Venice station VENF1, on the coast at Venice. Wind, gusts, pressure and air temperature. Its water temperature reading isn't always available.
- Buoy 42013, run by the University of South Florida on the 25-meter (about 82-foot) depth line, roughly 25 nautical miles west of Venice. Wind and water temperature from well offshore; its wave readings are often missing.
- Buoy 42098, at the entrance to the Tampa Bay shipping channel, about 9 nautical miles west of Egmont Key. Wave heights and periods, but no wind.
If the stations already show more wind than forecast, believe the stations. Our Sarasota page puts the latest forecast, these readings and the tides side by side.
The passes are their own weather
Some of the roughest water around Sarasota is in the passes. When the wind blows onshore against an outgoing tide, the waves in the mouth of Longboat, New or Big Sarasota Pass or Venice Inlet stand up steep and close together, even when the Gulf outside is moderate. Check the tide as well as the wind: the same pass can be easy on the incoming tide and ugly on the outgoing. NOAA's tide predictions for Sarasota and the stations listed in our passes guide give you the timing.
Know how far you're going
The bottom off Sarasota slopes very gently, so deep water is a long way out. Going due west from the beaches on NOAA's elevation model:
- About 30 feet: 2 to 4.5 nautical miles out. The Silvertooth reefs, in 25 to 33 feet, are about 2 nautical miles off Big Sarasota Pass.
- About 40 feet: about 7.5 to 8 nautical miles off Lido and Siesta keys, but only about 5 off Venice.
- About 60 feet: roughly 11.5 to 17 nautical miles out.
- About 100 feet: roughly 30 nautical miles out. FWC says gray triggerfish, which live alongside red snapper, are usually deeper than 80 feet.
A 30-mile run is a long way home if the wind comes up early, so build in a margin: watch the forecast for the afternoon as well as the morning, carry more fuel than you think you'll need, and turn back early if the stations start climbing. The 20-mile line in the forecast also matters here, because a trip to 100 feet puts you in the offshore zone, GMZ873.
And remember that the forecast lines are not fishing lines. State waters end 9 nautical miles out, and federal rules apply beyond that.
A simple routine
- The night before: read the synopsis and GMZ853, plus GMZ873 if you're going past 20 miles.
- In the morning: check that you're reading the latest issue, and look for new headlines.
- At the ramp: check VENF1 and 42013, and look at the pass you'll be running.
- On the water: keep an eye on the sky and leave yourself time to get back through the pass before the weather does.
Before you go
Check the conditions on our Sarasota page, tell someone where you're headed and when you'll be back, and keep a VHF radio on board. If you're heading for the reefs, our guide to Sarasota's artificial reefs covers what's at each depth.