Also, schedules change frequently, and special events modify the usual routine. Despite all this, most openings happen around the expected time, and most bridge tenders do their best to make it all go smoothly. In recent years, several boats have been struck by closing bridges. Always make sure the bridge tender knows you are coming. He or she may not have the best visibility from the small office high on the bridge, and could be distracted by a phone call or other activity.
Swing bridges are common, especially on the northern stretches of the Waterway.
These bridges pivot on a central turning point. Appendix A lists some bridges that have a preferred channel, but check with the bridge tender if in doubt. If there is a current running, its speed may increase as it squeezes through the constricted channel under the bridge. At some bridges, a crosscurrent will pull or push boats toward the wooden fenders. Commercial vessels may not be able to stop or maneuver in the narrow ICW channel, so always give them plenty of room at bridges.