Construction of Bohus Fortress, ten miles upriver from Gothenburg, began in 1308 by King Hakon V Magnusson of Norway to defend Norway’s southernmost border. Bohus was considered one of the biggest and strongest in the Nordic region—it survived 14 sieges and was never captured.

After passing through the flight of locks at Trollhattan, we continued south along the Gota Alv river, exiting the final lock on the Trollhatte Canal at Lilla Edet. Back at sea level after first entering the Gota Canal more than three weeks earlier, we stopped for the night below Bohus Fortress to expolore the castle ruins and the nearby town of Kungalv.

Below are trip highlights from August 27th, 2019. 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.

Upper Lock Position: 58°15.94’N, 12°15.86’E Entering the first of four locks at Trollhattan. Each lock is about 30ft (9m) deep and we’ll descend a total of 127ft (38.9m).

Swapping Lines Position: 58°15.93’N, 12°15.81’E The Trollhatte locks have fixed bollards set into the lock walls that are about 15ft (4.5m) above each other. The bollards are sufficiently far apart that we can only easily reach one from Dirona, so we just use one line pulled tight amidships to hold us against the lock wall. We gently let line out as the boat descends, and once we’re down about 15ft we put a second amidships line onto the bollard that is now visible close to the water line. Once it’s holding securely, we release the line above and essentially just crab our way down the lock wall.

Gates Opening Position: 58°15.93’N, 12°15.81’E The gates opening at the upper Trollhattan lock.

Entering Flight Position: 58°15.90’N, 12°15.42’E Entering the flight of three locks at Trollhattan.

Opposing Traffic Position: 58°15.90’N, 12°15.37’E As with the pleasure craft we’d watched earlier, the upper middle locks are brought to the same level with pleasure craft in each and they pass each other in the locks. This is more efficient in that boats can be moving down the flight of locks at the same time that others are moving up, but it’s not a very common approach. Most flights we’ve been in move one or more boats all the way down or up before running the other way.

Middle of Flight Position: 58°15.90’N, 12°15.29’E In the middle of the three-lock flight, looking down to the lower lock.

Lilla Edet Position: 58°8.37’N, 12°7.34’E James taking us into the final lock on the Trollhatte Canal at Lilla Edet. This will bring is down 21ft (6.4m) to sea level.

Bohus Fortress Position: 57°52.26’N, 12°1.33’E Bohus Fortress, our destination for the day, dominates the landscape as we approach.

Dirona Position: 57°51.63’N, 11°59.96’E Dirona moored behind Bohus Fortress.

Sheep Position: 57°51.63’N, 12°0.03’E The land around the fortress is full of sheep. Some were even walking on the dock beside the boat. This one believes it’s the stand-on sheep and that Jennifer will have to give way.

Blockhus Gate Position: 57°51.71’N, 11°59.93’E At the Blockhus Gate entrance to Bohus Fortress. Construction of the fortress began in 1308 by King Hakon V Magnusson of Norway to defend Norway’s southernmost border. Bohus was considered one of the biggest and strongest in the Nordic region—it survived 14 sieges and was never captured.

Fars Hat Position: 57°51.73’N, 11°59.93’E The large northern tower Fars Hat (Father’s Hat) at Bohus Fortress.

Dungeon Position: 57°51.72’N, 11°59.96’E The medieval dungeon in Fars Hat. Prisoners were lowered into the 20ft-deep (6m) chamber through a hole in the floor and the hatch was then covered, admitting no daylight at all.

Fortress Model Position: 57°51.72’N, 11°59.96’E Model of Bohus Fortress showing how it looked when in use.

Fontin Fortress Park Position: 57°51.98’N, 11°59.87’E We walked into the nearby town of Kungalv through Fontin Fortress Park. The park had wonderful trails and several excellent viewpoints. This is looking back to Bohus Fortress. Dirona is moored in the river on the other side. The water is too shallow for us to reach or moor at the marina in the foreground.

Gustus Gastrobar Position: 57°52.25’N, 11°58.94’E An excellent meal with local microbrew on the wonderful patio at Gustus Gastrobar. It was still so warm that we wanted to be out of the sun.

U 137 Position: 57°51.65’N, 11°59.91’E A concrete foundation in the river looks like a submarine, so was painted with the markings of U 137, the Soviet submarine that went aground near Karlskrona on the southeast coast of Sweden during the Cold War.

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.