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Which bridges on my route are lower than my mast?
Pick a waterway, enter your air draft. You get every bridge whose published clearance is lower than your air draft plus the margin you chose. The comparison is arithmetic on published figures – it does not tell you what your boat will do under the bridge.
Clearances are published at Mean High Water. Tide, wind, waves and lake level change what is really there.
- Published at mean high water. Vertical clearances of bridges and overhead cables are in feet above mean high water unless otherwise stated.
- A higher water level leaves less room. When the water level is above Low Water Datum, the bridge and overhead cable clearances given in the Coast Pilot and shown on the charts should be reduced accordingly.
- Drawbridges. Clearances of drawbridges are for the closed position, although the open clearances are also given for vertical-lift bridges.
- Where the figures come from. Clearances given in the Coast Pilot are those approved for nautical charting; most are supplied by the U.S. Coast Guard for bridges and the U.S. Army Corps of Engineers for cables.
- Read the gauge. The Coast Guard regulates clearance gages on bridges across navigable waters. Where installed, clearance gages are generally vertical numerical scales, reading from top to bottom, and show the actual vertical clearance between the existing water level and the lowest point of the bridge over the channel; the gages are normally on the right-hand pier or abutment of the bridge, on both the upstream and downstream sides.
Every bridge in the guide, grouped by waterway, with its published clearance.
ICW Fernandina → Fort Pierce
| Bridges | Mile | Type | Vertical clearance | Datum |
|---|---|---|---|---|
| Broadway Bridge | 830.1 | fixed | 63 ft | MHW |
ICW Fort Pierce → Miami
| Bridges | Mile | Type | Vertical clearance | Datum |
|---|---|---|---|---|
| Julia Tuttle Causeway (Thirty-Sixth Street) | 1087.1 | fixed | 56 ft | MHW |
Miami → Keys, inside
| Bridges | Mile | Type | Vertical clearance | Datum |
|---|---|---|---|---|
| Fixed highway bridge at Barnes Point | 1126.8 | fixed | 65 ft | MHW |
| Highway bridge at Cross Key | 1134.1 | fixed | 67 ft | MHW |
Okeechobee Waterway
| Bridges | Mile | Type | Vertical clearance | Datum |
|---|---|---|---|---|
| Railroad lift bridge at Port Mayaca | 38 | lift | 49 ft | referred to a St. Lucie Canal stage of 14.5 feet |
| Fixed highway bridge at Palm City | 9.5 | fixed | 54 ft | MHW |
| Caloosahatchee Bridge (U.S. Route 41) | About 0.5 mile southwest of the Edison Memorial Bridge | fixed | 55 ft | MHW |
| Martin Highway fixed bridge | 10.4 | fixed | 55 ft | MHW |
| Thomas B. Manual (Florida Turnpike) Bridge | 14.5 | fixed | 55 ft | MHW |
| State Route 710 highway bridge at Indian Town | 28.1 | fixed | 55 ft | referred to a St. Lucie Canal stage of 14.5 feet |
| U.S. Route 98–441 highway bridge at Port Mayaca | 38.8 | fixed | 55 ft | referred to a St. Lucie Canal stage of 14.5 feet |
| U.S. Route 27 twin highway bridges at Moore Haven | 78.4 | fixed | 55 ft | MHW |
| I-95 twin fixed highway bridges | 14 | fixed | 56 ft | MHW |
| State Route 76A fixed highway bridge | 17.01 | fixed | 56 ft | referred to a St. Lucie Canal stage of 14.5 feet |
| Edison Memorial Bridge (U.S. Business Route 41) | 134.5 | fixed | 56 ft | MHW |
GIWW Panhandle
| Bridges | Mile | Type | Vertical clearance | Datum |
|---|---|---|---|---|
| Overhead power cable, St. George Sound | Mile 363.0E | cable | 46 ft | MHW |
| Brooks Bridge | Mile 223.0E | fixed | 50 ft | MHW |
| Dupont (SR-30/US-98) Bridge | Mile 295.5E | fixed | 50 ft | MHW |
| Navarre Causeway Bridge | Mile 207.0E | fixed | 50 ft | MHW |
| Mid-Bay (SR-293) Bridge | Mile 234.2E | fixed | 64 ft | MHW |
Not a navigation aid. Published clearances are not a promise about your boat.
Sources & checks
- NOAA U.S. Coast Pilot 4, chapter 1, "Bridges and Cables" (18 OCT 2026) · 18 Oct 2026
- NOAA U.S. Coast Pilot 4, chapter 12, Atlantic Intracoastal Waterway (18 OCT 2026) · 18 Oct 2026
Written by buoya editorial from the sources above. Every figure was checked against its source on 22 Oct 2026. Found something wrong? Report a correction.