the Degree Confluence Project


1.9 km (1.2 miles) S of Marin, Neuchâtel, Switzerland
Approx. altitude: 428 m (1404 ft)
([?] maps: Google MapQuest OpenStreetMap ConfluenceNavigator)
Antipode: 47°S 173°W

Accuracy: 4 m (13 ft)
Quality: good

Click on any of the images for the full-sized picture.

#2: Sandy ground at the Confluence #3: Some Water Plants: Potamogeton pectinatus #4: 20 m from the Confluence: Potamogeton lucens #5: Confluence Hunter holding Preserving Jar #6: GPS Reading #7: Panorama West #8: Panorama East #9: Swan and Family #10: Place du Marché in Neuchâtel

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  47°N 7°E (visit #5)  

#1: The Confluence in 5 m below water surface

(visited by Rainer Mautz and Elionora)

14-Jun-2008 -- For half a year various investigations have been preceding this visit before we finally could accomplish our goal.

According to the rules of confluence.org "you must be on the Earth's surface" in order to submit a complete visit. If you interpret that the earth's surface is where the atmosphere touches solid ground, all 500 water-confluence visits that have been carried out so far on board of ships or boats would count as incomplete. This inspired me to take underwater pictures of the sea floor. Since diving was no option for me, I focused on how to bring at least a camera down to the sea bottom.

However, this task turned out to be difficult. The obvious idea was to use a waterproof camera or a watertight underwater housing for my camera. Both options turned out to be costly. Moreover, the maximal watertightness is restricted to depth 20 – 50 m, which would not be sufficient for documenting most of the water-confluences. Anyway, there was no need for a function for full camera control, because I couldn't accompany the camera underwater. The idea was to use the "interval timer" functionality which is a mode where the camera automatically takes a picture every minute. In order to keep my camera dry, I wanted to put it in a preserving jar and let it down to the sea-floor on a string. But it was winter – a time where shops didn't have preserving jars for offer.

I ran all around Zurich, but wasn't able to obtain a qualified jar. Finally, my direct neighbour – an old lady brought me one up from her basement. With enthusiasm I carried out some tests in a bucket. My sense of delight was clouded by the fact that the jar was not really water-proof. Any pictures taken from inside turned out to be milky and distorted. So I temporarily gave up the idea with the jar and considered to use an open container with a bell shaped top. The camera in the top should stay dry while the air inside would be condensed according to the water-depth. This experiment however was never carried out due to practical reasons: the difficulty of finding or manufacturing such a "thing" that I had in mind.

Progress was on hold until summer came. One day when I was shopping for groceries, I saw that the season's delivery of preserving jars had just arrived. I bought a nice transparent one. The new rubber seal turned out to be waterproof and the pictures showed hardly any distortions. Before I actually went to the confluence, I carried out several tests in the nearby Lake Zurich. Hereby, the lessons I learned were:

  • That all tests need to be preceded with a valueless weight before actually risking a camera.
  • That the flash needs to be avoided, because the light gets reflected at the jar.
  • The advantage of using lead with its 11.34 g•cm−3 for additional weight.
  • To make the container heavy enough that it sinks down quickly enough.
  • That a too low weight causes the jar to tilt over at the sea floor.
  • To adjust the weights properly in order to minimise the tilt.
  • That nevertheless a heavy, well balanced weight never guarantees that the jar doesn't tumble down due to a rough sea-floor.
  • That it is best to turn off the auto focus in order to avoid that particles in the water get focused instead of the underwater landscape.
  • That the jar tends to rotate and causes blurred pictures.
  • And finally, that this is fun and one can shoot interesting pictures this way.

On confluence day we got up at 5:40 a.m. in our home in Zurich. We took a train (2 hours) via Bern to a tiny station called Gampelen, which is 5 km beeline from the DCP). From Gampelen we had a 2-km walk to the campground "TCS-Campingplatz Fanel". Mr. and Mrs. Eschler, the owners of the campground rent out three types of boats: canoes, pedal boats, and kayaks. After a quick inspection we opted for the canoe – being wide enough to keep us and our equipment dry and safe. Now we had to paddle 3 km beeline to the confluence. With speeds around 4 and 6 km/h we reached the confluence within 45 minutes. Obtaining an exact zero-reading at the GPS receiver turned out to be more challenging than it would be on land. We circled around for 15 minutes until we finally got all zeros. But when the camera was ready, the last digit wasn't a zero anymore.

Then the exciting moment had come to let down into the water our "preserved" camera. The jar sank down and after winding up about 5 m from the line I could feel that it had hit the ground. All my previous tests had been carried out from land. Now I learned that from a boat an additional difficulty can arise: the boat drifted away and the line got under the boat, confusing the line and us as well. However, we managed somehow by letting the boat drift away and continuously uncoiling more and more from the roller. We waited a minute or two, lifted the jar up for a short moment and then gave it another minute on the ground to take another picture. We repeated this procedure several times in order to get various directions at slightly different locations. When we looked at our results, we were disappointed: just blurry monotonous green. We adjusted the weights, tuned out the auto focus and repeated the procedure: this time with success, we got pictures #1-3. Interestingly, picture one shows some "hills" or overgrown stones, while the other two pictures show a sandy plane with some underwater plants (Potamogeton). The distance between the locations of the pictures is around 5 m. 20 m from the confluence we encountered some long structures of pondweed, probably it is Potamogeton lucens.

We then paddled on shore to have a picnic as lunch break. We cruised back to the camp ground by following the shore-line. Thereby, we observed the wonderful wildlife at Lake Neuchâtel. After our arrival at the campground at 4:30 pm, we hiked 10 km along the shore to the city of Neuchâtel (being 5 km beeline from the confluence). Here we had our deserved dinner at the Place du Marché. Around midnight we were back home.

CP visit details:

  • Time at the CP: 11:00 – 12:00 am
  • Paddle distance: 3.1 km (beeline, from campground in Gampelen)
  • Paddle time: 55 min
  • Hiking distance: 2 km (from train station Gampelen)
  • Hiking time: 30 min
  • Train time: 1 h 51 min (from Zurich)
  • Distance from lakeshore: 470 m
  • Water depth: 5 m
  • Distance to a track: 500 m
  • Distance to houses: 700 m
  • Topography: flat (bottom of lake at DCP)
  • Minimal distance according to GPS: 1 m
  • Position accuracy at the CP: 4 m
  • GPS height: 431 m (water surface), 426 m (lake bottom)
  • Vegetation: Aquatic plants: Potamogeton lucens and Potamogeton pectinatus.
  • Weather: alternating sunny, overcast, light rain, 15-20° C (felt temperature)
  • Description of the CP: At the north-eastern end of Lake Neuchâtel, 470 m from land, in shallow water, bottom of lake covered sand and scattered rock-formations
  • Given Name: The First Underwater Confluence

 All pictures
#1: The Confluence in 5 m below water surface
#2: Sandy ground at the Confluence
#3: Some Water Plants: Potamogeton pectinatus
#4: 20 m from the Confluence: Potamogeton lucens
#5: Confluence Hunter holding Preserving Jar
#6: GPS Reading
#7: Panorama West
#8: Panorama East
#9: Swan and Family
#10: Place du Marché in Neuchâtel
ALL: All pictures on one page
In the Lac de Neuchâtel, about 470 m from the lakeside.