January 2011

Clear the bridge

Navigate inland waterways safely

Approach bridges slowly and cautiously, making sure your wake doesn’t create problems for other boats.

Many inland lakes and rivers have no minimum bridge height. Maps and charts show the center channel span with its horizontal and vertical clearances.

To be sure your boat will safely clear the bridge, refer to the clearance gauge affixed to the bridge’s right side upon approach. The gauge marks the distance between the bridge channel span and the waterline, not the water depth under the bridge.

At night, a green light marks the center of the navigable channel under a bridge, and red lights mark supporting piers. Stay clear of the piers as you may be unable to see protective framework until it’s too late. Strong currents, exposed rock and trapped debris can also be present.

To determine a drawbridge’s clearance, contact the bridgetender on VHF Channel 13 or 16 (Channel 9 in Florida, Georgia or South Carolina) using the low power (1 watt) setting.

Never ask for an opening if your boat will fit under a closed bridge. You must lower radio antennas or movable masts if necessary.

If you can’t talk to the bridgetender on VHF, you can request an opening with one long (4–6 second) and one short (1 second) blast. The bridgetender will return the signal if the bridge can be opened immediately. If the bridge cannot open or is closing, the tender will sound the danger signal—five short blasts.

Not all lift bridges open on demand or on a set schedule. Railroad drawbridges can stay down for hours. Local knowledge is essential if you don’t want to get stuck between a drawbridge and a railroad bridge while waiting for the latter to open.

For more information on navigating inland waterways, take the Boating on Rivers, Locks and Lakes seminar at a squadron near you.

Stay warm in cozy sweaters at the USPS Ship's Store!

Mastering Marlinespike

Blood knot

When you need a stopper knot larger than an overhand knot, the decorative blood knot is ideal.


Archive | USPS | The Ensign | Privacy Policy | Subscribe to USPS Compass

Facebook badge  Find us on Facebook | Twitter badge  Follow us on Twitter | WordPress logo  Read the USPS Stargazer blog

ISSN 1946-1313 © 2013 United States Power Squadrons. All rights reserved.

1504 Blue Ridge Road • Raleigh, NC 27607 • 888-367-8777

Boating is fun ... we’ll show you how!

Visit USPS Compass Online Visit United States Power Squadrons online