A collection of blogs and musings from the people that work at the St. Augustine Lighthouse & Museum - Florida's Finest Lightstation.

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Sonar Survey on the 'Total Blarney'

Posted by: Renee Post in LAMPosts

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Maj. Gen. Gerry Maloney's yacht, Total Blarney.

Maj.Gen. Gerry Maloney, president of the board of directors for the SALH, was kind enough to take us on his 37’ Carver s to survey the Gulf America with our new side scan sonar. Our team of three, Chuck Meide, Brendan Burke and myself, Renee Post, left the lighthouse about 9:00 A.M. We arrived at Gerry’s boat shortly before 10:30, in Jacksonville, and loaded our equipment onto his luxurious vessel. We were pleasantly surprised to discover that the research craft for the day was much more comfortable than we could have expected. The Total Blarney’s cabin had more than enough room for us to work and the air conditioned environment helped protect our equipment from the salt spray. In the cabin, a nice bench-like sofa made a great work station for our sonar laptop. After we loaded the boat we secured the GPS antenna for the sonar computer to the Total Blarney’s stern, while we headed to the lock.

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The lock when full.

Total Blarney entered the lock’s gate and the lock attendants threw us lines to tie off the boat so that as the water level lowered, the vessel would not collide with the locks walls. The attendants pumped the fresh water from the lock back into the canal and soon we were on our way down the St. John’s River toward the inlet.

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The lock after Total Blarney was lowered to the river's water level.

The ride down the river was quite smooth and we continued to assemble our equipment. First, we ran a cable from the GPS antenna through a window in the cabin and connected it to the GPS receiver. Next, we connected the GPS receiver to the sonar computer and the sonar laptop to the sonar computer.

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Brendan Burke showing Renee Post how to connect the GPS antenna cable to the GPS receiver.

The sonar tow fish bounces ‘pings,’ or short pulses of sound, off the riverbed and produces a near photographic quality image. The laptop contains software that allows us to view the data as an image received from the sonar computer. Our goal was to survey the Gulf America, a WWII oil tanker that sunk when it was hit by a torpedo from a German U-boat. We ate our lunch on the way out to the inlet and seas began to build.

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Gerry at the helm.

Unfortunately, once we reached the inlet the water became quite rough, even for the Total Blarney, as the seas were as high as six to eight feet. We pressed on for a short distance as the spray turned into showers and everything on the boat that was not secured was flung about, including ourselves. In fact, our pineapple upside down cake ended up right-side up! We decided to turn back when the bow dipped below the waves and we heard a crash below. One of the lights in the head broke while Brendan was closing a hatch in the head, barely missing his feet.

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Brendan getting sidescan sonar towfish ready for deployment.

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Sonar fish in the water.

We did not get to survey the Gulf America, but instead we decided throw the tow fish in the water and get some sonar images of the riverbed instead. Once we entered an area where the water was calm enough, we lowered the fish into the water and began collecting data, so that we could become more familiar with our new equipment and introduce me to how the equipment works. We could see depressions in the riverbed, day markers and even the shoreline. Gerry righted our upside down cake and kindly served us while we watched the sonar image scroll up the screen.

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Chuck Meide and Renee watching real-time sonar images of St. Johns River bottom.

We quickly finished playing with our wonderful new toy and returned to the lock, where we were lifted back to canal level. Total Blarney returned to the boat slip about 2:00 or 2:30 and unloaded the boat. Our team helped Gerry wash his beautiful yacht and we could see the salt run into the freshwater in a milky haze. Brendan sprayed the decks and hull with water, I scrubbed the remaining salt from the surfaces and Brendan rinsed it away, while Chuck got stuck with the windows. After we finished with the yacht we rinsed the equipment and loaded it into the truck to head back to St. Augustine. It was a beautiful first day on the job!

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Brendan and Renee hauling sonar equipment from Total Blarney.

Comments (2)

I am looking at a Klein 3900 for purchase like the one in this article for SAR work. Would be interested in feedback from the owners of this unit as to how they have likes it if they would be so kind as to reply.
Thanks
Randy

Hi Randy,

We're very happy with the Klein 3900. Its durable, heavy-duty, easy to use, and produces a high quality image. You should be able to find some more examples of images we have generated with this unit on other entries in this blog (check out the images of the wrecked dredge Florida, posted in August 08). Feel free to contact us if you want more info--you can find our contact information through the LAMP or St. Augustine Lighthouse & Museum webpage. Good Luck!

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