SR 520 floating bridge - Boater info

Lake Washington boater information

To receive updates about boating activities and navigation restrictions on Lake Washington, email us at SR520Bridge@wsdot.wa.gov and ask to be added to the boater-notification list. Notification emails will be on an as-needed basis.

Navigation restrictions

For the latest SR 520 navigation restrictions on Lake Washington, please visit the "Over-water and in-water work" section of our Construction Corner.

Floating bridge navigation channels

During Montlake Project construction, one navigation channel may be blocked periodically for critical construction work. During these blockages, marine vessels should plan to navigate through the unaffected channel (see below for navigational height restrictions). At least one navigation channel will always be open and accessible to boaters.

A number of graphic that show the state route 520 floating bridge and the eastern and western navigation channels and their heights.
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East navigation channel's clearance under the new SR 520 floating bridge

At the east navigation channel, boaters will see two signs indicating clearance heights. Both signs are gauges posted at the water level to show the clearance for boaters at the current water level. The graphic below shows the east navigation channel's clearance under the new SR 520 floating bridge.

A sign currently is posted on the pontoon located at the west side of the east channel. While this sign is a gauge, as shown below, the sign will always show a clearance of 70 feet at water level since the pontoon rises and falls with changes in water levels on Lake Washington.

Another sign is posted on the fixed, east approach column along the east side of the channel. The clearance typically is 65 feet at the east end of the channel, so boaters will see that portion of the sign at water level. When water levels lower, the clearance on the east side of the channel may rise to approximately 67 feet.

A graphic of a bridge over water with two pillars on either side of a navigation channel. Signs on the left pillar show a clearance of 70 feet with signs on the right pillar show a clearance of 65 feet.
East navigation channel height under the new SR 520 floating bridge.
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Nautical mile markers

The new SR 520 floating bridge has nautical mile markers to indicate distance for boaters on Lake Washington. The markers are placed on both the north and south sides of the bridge. The graphic linked below shows the layout for the nautical mile markers.

A diagram of the state route 520 floating bridge. On either side of the bridge are markers that signify the location of a nautical mile marker.
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