Most of the bridges in The Florida Keys are shown on Sketch Charts 13, 14, and 15. Fortunately for the majority of us, however, cruising in the Keys means “no bridges to worry about.” If you opt for taking Hawk Channel down the ocean side you can cruise from Biscayne Bay all the way to Key West and never have to wait for a single bridge to open; “vertical clearance” simply doesn’t matter. The only working draw bridge that remains in the Keys is across Snake Creek and the shallow approach waters on the Hawk Channel side can often be as limiting to cruising vessels as the 25-foot closed clearance of the bridge itself. If you can handle the depths but need more height, Snake Creek Bridge will open on the hour and half-hour from 8 AM to 4 PM. daily, and on demand at all other times.
The other major passages from ocean to Bay-- and from sound to sound on the Bay side-- are now spanned by bridges that offer 65-foot clearance at high tide. There are also other “safe water” passages all along the Keys, but with the exception of Indian Key Channel, where the fixed bridge offers 27-feet at center, the bridges along the Overseas Highway mostly present little more than ten or twelve feet of vertical clearance. This means that for cruising vessels, and even many fishing boats, the only practical way to get from Bay side to Ocean side involves using a major channel, which will offer both suitable depths, and also ample clearance under the bridge.
Skipers who choose to cruise down the Bay side should remember that the last passage to the ocean side will be at Bahia Honda Channel, where the vertical clearance of the inner (highway) bridge is a mere 20 feet. Though masted vessels approaching from Hawk Channel can now use the Bahia Honda Anchorage or Marina (thanks to the removal of a section of the old railroad bridge), vessels passing from Bay to Ocean still face that 20-foot limitation. Vessels needing greater height should head out just below Marathon using either Knight Key Channel, which is closer to Marathon if the 19-foot Vertical clearance is sufficient, or heading down to take Moser Channel under the Seven Mile Bridge, which offers 65’ of clearance over the main channel.