We’d passed over vehicle roads in Dirona several times, for example in Boston Harbor and Norfolk, Virginia, where a vehicle tunnel runs under the waterway. But until we transited the Krabbersgat naviduct, near Enkhuizen, we’d never passed through an aqueduct over an open road.

A naviduct is a special type of navigable aqueduct that also includes a lock. The only two we are aware of in the world are the Krabbersgat naviduct in the Netherlands and the Seneca Aqueduct on the Chesapeake and Ohio Canal in the US, constructed in the early 1800s. The Krabbersgat Naviduct, completed in 2003 at a cost of €55 million, is the most modern and largest in the world, capable of carrying two large Rhine river barges. It sits at the intersection of a busy waterway and a high-traffic road and was built to replace an existing lock that resulted in long delays for both road and water traffic. Space was too limited to built a tunnel or carry the road sufficiently high over the waterway to avoid an opening bridge, so the waterway was carried over the road instead.

Below are trip highlights from October 30th at Krabbersgat naviduct in the Netherlands. Click any image for a larger view, or click the position to view the location on a map. And a live map of our current route and most recent log entries always is available at mvdirona.com/maps

Naviduct Position: 52°41.43’N, 5°17.48’E We rode the bikes over this morning from Enkhuizen to check out the naviduct before passing through. Here you can see vehicles passing under the waterway with the lock control tower at left.

Aqueduct Position: 52°41.48’N, 5°17.70’E The aqueduct carrying boat traffic over the road between the Markermeer and the IJsselmeer lakes.

Lock Position: 52°41.49’N, 5°17.72’E The locks are what make the aqueduct a naviduct. Although the two lakes at either end have the same target water level, wind surge and feed flows can cause differing water levels. The locks are each 410ft (125m) long by 41ft (12.5m) wide and can accommodate large Rhine River barges.

Old Lock Position: 52°41.56’N, 5°16.98’E Prior to the construction of the naviduct, boats had to pass through this lock and a bridge that required opening for vessels with an air draft of greater than 19ft (6m). The delays for both boat and vehicle traffic were substantial, so the naviduct was built at a before-tax cost of €55M to eliminate vehicle delays and reduce vessel traffic delays.

River Queen Position: 52°41.87’N, 5°17.41’E We watched the River Queen river cruise ship arrive at Enkhuizen this morning via the naviduct and stopped by the on our way back to our berth at Enkhuizen. The ship is designed after a 1930s river steamboat and has a opulent Art Deco interior.

Power Position: 52°41.86’N, 5°17.46’E We often see three-phase power supplied here on five separate cables, one for each phase (brown, black and grey in the photo) plus ground (green) and neutral (blue).

Allegro Position: 52°41.85’N, 5°17.43’E The Enkhuizen-based river cruise boat Allegro moored adjacent to the River Queen.

Train Station Position: 52°41.98’N, 5°17.48’E Enkhuizen’s train station opened in 1885.

Green Light Position: 52°41.54’N, 5°17.76’E After returning to Dirona, we loaded our bikes and got underway for the naviduct, only a few minutes away from our Enkhuizen berth. The green light about center of the picture shows that we can enter the naviduct lock behind a large commercial barge.

Gate Closing Position: 52°41.48’N, 5°17.74’E The naviduct lock gates closing behind us.

Locking Through Position: 52°41.47’N, 5°17.74’E Locking through with traffic passing underneath the aqueduct.

Exiting Naviduct Position: 52°41.44’N, 5°17.73’E Passing over a truck as we exit the naviduct.

Click the travel log icon on the left to see these locations on a map, with the complete log of our cruise. On the map page, clicking on a camera or text icon will display a picture and/or log entry for that location, and clicking on the smaller icons along the route will display latitude, longitude and other navigation data for that location. And a live map of our current route and most recent log entries always is available at mvdirona.com/maps.