Multibeam SONAR on Kosrae

At long last we were finally able to see SONAR in action as a measurement tool.  We’ve been laser scanning, surveying, etc. for many years so this was really exciting for us – ok maybe just for Pete.  Luckier still we got to see it in use on beautiful Kosrae (Micronesia).

The plan, as part of the Knowledgewell project, was to scan the Lelu Harbor on Kosrae.  It had never been done and there were several known wrecks on the bottom – both ships and aircraft.  As you can see from the images the data is gorgeous and four shipwrecks and two plane wrecks can be seen.  We know that the largest ship was a Japanese freighter carrying coal.  What is interesting about this wreck is that the ship sank while at anchor.  How do we know this?  Because the anchor chains are out and the gangway can be seen alongside.  No one knew this . . . so this was a new discovery!  The other ships appear to be a barge, an old, wooden whaler, and a to be identified ship.

PBM Wreck
PBM Wreck

The aircraft presented a bit of a surprise as well.  We had been told that there was a WWII PBM wreck on the reef.  The story goes that the US Navy sent a delegation to accept the Japanese surrender of the island on board this PBM.  After the business was done the PBM crashed on takeoff.  What we were not prepared for was the second PBM wreck.  Only when Pete was checking bags at the airport to leave Kosrae and chatting with a local did he learn that another PBM had crashed on takeoff back in the early 60s.  This gentleman had witnessed the crash as a child.  Before there was an airport on Kosrae the only way on and off the island quickly was via floatplane so the WWII surplus PBMs were the workhorses for getting sick and injured folks off the island in a hurry.  He said that everyone on board had been killed in this crash.  Fascinating to have witness testimony so many years later . . . and now we have models of the wreck sites forever.

In the coming weeks we will add the SONAR data to the existing model of the island that Pete created back in 2007.  A HUGE thank you to Jens, Charles from R2Sonic.  Without their generosity, skill, patience and good humor the project would not have been possible.  More to come as the models are created . . .

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