Cha'ba buoy deployment

As we've mentioned in past posts, we deployed the Cha'ba buoy on Tuesday morning.

The Cha'ba crew rallied on deck pre-dawn for the final prep before deploying the buoy into the water. 

The Thompson has quite the winch system on board that is able to lift the buoy and get it in the water. Buoys can be deployed in two different ways: top first, where the buoy is put in the water first and the anchor last; and bottom first, where the anchor is deployed first and the buoy last. Cha'ba was deployed top first.

Where the winch and pulley pulls the buoy vertically, the A-frame, or the structure that you can see in the above photo that the pulley is attached to, is able to move from straight vertical to an angle over the water moving the buoy horizontally.  Once the buoy is dangling over the water, the winch then slowly lowers it into the water.

 After the buoy was in the water, all the sensors along the line hanging below the buoy needed to be attached. The buoy is in about 100 meter depth (about 300 feet), and there were 40 sensors that needed to be attached along the line that is about the same length as the depth of the water.

UW grad students Angie and Andy add sensors to Cha'ba's mooring line.

The above photos show two grad students attaching the sensors as the pre-defined locations marked by pieces of duct tape. It took about 3 hours for all the sensors to be attached.

One of the last pieces of equipment that needed to be attached is a larger sensor package plus glass floats held in the yellow plastic cases. The yellow floats are part of the buoy retrieval system. When the buoy is retrieved, it is picked up in reverse order of the deployment, so the anchor gets pulled up first. While the buoy is deployed, these floats are attached to the line close to the anchor. When the crew comes back to pick the buoy up, they will use an acoustic trigger to release the floats which will then come to the surface. The crew will then hook the floats and pull the anchor on board first, and the pull in the the rest of the line and eventually the buoy.

The last piece is the anchor, which is actually four train wheels stacked on top of each other.

Soon after Cha'ba was deployed, the data started streaming! You can find the real-time data from Cha'ba on the NANOOS Visualization System's Data Explorer web app.