Survey dive on another unknown barge in Lake Washington.

On Monday we dove an unknown wreck north of the 520 Bridge. We had been getting very odd side scan imagery with little to no ability to cast shadowing that would make much sense or give us an idea of what was located in the area. With that in mind we decided to dive the site and conduct a preliminary survey.

It turns out that this wreck is a flat deck work barge that had a large structure built on the upper deck. When it sank it tipped on its side and nosed down into the muddy bottom of the lake. This all steel barge appears to have hit quite hard as it is standing on its side with and at a 45 degree angle out of the mud.

barge-out-of-water.gif

This picture shows a similar looking barge.  Note the flat bottom.

This large barge (75'+ in length, 35' wide) has it highest point in just 140’ of fresh water sloping down to the mud line at 196’. The flat bottom is vertical in the water column and easily navigated.  Unfortunately the other side of the wreck had the exposed remains of the structure protruding. Divers having to search for the wreck and approaching from the Northeast will quickly find themselves either under the elevated stern section or swimming into the structural remains before they realize where they are in relation to the wreck.

BargeWithStructure.gif

This picture shows a structure built on a flat deck work barge.  The structure on this wreck was constructed of corrugated tin roofing materials, wood framing, and thin metal walls.

On today’s dive we were working with multiple coordinates obtained from our side scan imagery and were able to place our drop line exactly where we intended. This allowed the search to be conducted in green water at 150’ rather than on the bottom. Our impression of the wreck as potentially hazardous was correct and, while more difficult, this approach potentially saved us a bunch of grief. Ben Griner and Shaun Garder dove this wreck with an average depth of 180' and max depth of 196'.  A total of 25 minutes was spent conducting the survey.  Scott Christopher acted as captain and picked us up after our decompression.

I strongly recommend that this site not be dove. The potential of inadvertently entering into an overhead situation is high and complicated by the instability of the overhead structure. Most of the structure is very fragile and what penetration was conducted during the survey resulted in heavy percolation and dislodgement of debris from our bubbles. There is little to see at this site and with so many great wrecks in the lake this one could be ignored.