Bill Lindquist: The Small Boats, May 10, 2013

NOAA Teacher at Sea
Bill Lindquist
Aboard NOAA Ship Rainier
May 6-16, 2013

Mission: Hydrographic surveys between Ketchikan and Petersburg, Alaska
Date: May 10, 2013

Weather on board. Taken at 1600 (4:00 in the afternoon)
Latitude: 55° 47.29’ N; Longitude 130° 58.27’ W

Broken skies with a visibility of 10+ nautical miles
Wind from the west at 15 knots
Air temperature 12.6° C
Sea temperature  8.9° C

Science and Technology Log: The Small Boats

Yesterday the ship captured most of the ocean basin using its multibeam sonar equipment located on the bottom of the ship. Today we set out in smaller launches that could take us to the sections of the ocean the big ship couldn’t. Three teams were deployed, each containing a coxswain (person who has the skills to handle the boat), senior hydrology technician (in charge of the survey work to be done), and several others to help – one boat of which was gracious enough to take along a rookie “Teacher of the Sea” to experience first hand the work involved.

Moving the launch off the ship into the sea.
Moving the launch off the ship into the sea.
Trying out driving the boat is a prescribed line (harder than it would appear).
Trying out driving the boat in a prescribed line (harder than it would appear).

We all met on the fantail (rear deck) of the ship at 6:30 AM to go over the work that lays ahead. From there the launches were lowered off the ship, we entered, were released, and off we went. While still in the early morning low tide we examined the shoreline to verify the existence or non-existence of rocks in question from the last survey. We conducted our surveys throughout the rest of the day in areas not able to be accessed by the larger ship. Each launch is also equipped with multibeam sonar units on the bottom of the boat (image) and a plotting computer on board. As with the ship, the computer measures and controls for location (GPS); heave, pitch, and roll; and the temperature and salinity of the water column below our boat.

The multibeam sonar units on the bottom of the launch.
The multibeam sonar units on the bottom of the launch.
The plotting computer aboard the launch.
The plotting computer aboard the launch.

The work is similar, yet has a different feel. Unlike the automated features on the ship, a control panel allows the surveyor to hand tune variables that will help assure the best measurements. We can control the strength of the sound waves leaving the boat, the frequency of pings, wave length, and the degree of sweep that will be collected. Doing so allows us to maintain sufficient strength to capture tbe bottom, but not so overpowering that we lose the finer details such as the makeup of the bottom. Each boat sets a path back and forth at a speed of 7-10 knots in the sections assigned by the FOO (Field Operations Officer). This is repeated until each section is covered. This takes a concerted and collaborative effort between the coxswain and technicians. When surveying from the ship, the Moving Vessel Profiler’s fish can be cast by the push of a button at the computer in the Plotting lab. Not so on the launch. After bringing the boat to a stop, we lift over the CTD (conductivity, temperature, depth) instrument. We allow it to drop to the bottom before we turn on the winch to reel it back in. It is lifted out and attached to a cable connected to the computer where the data is downloaded.

The CTD sensor unit
The CTD sensor unit
Deploying the CTD
Deploying the CTD
One of the screens on the plotting computer indicates the areas that have been surveyed (in blue) and where the ship is.
One of the screens on the plotting computer indicates the areas that have been surveyed (in blue) and where the ship is.

Before we get back to the ship, we download the day’s data to an external hard drive and hand it off to another crew that begins the job of cleaning the data to be pieced together with all the other sections of data. We end with one complete picture of the project area.

Life at sea

There are 46 people living and working on board the ship. The launches go out with a smaller group of 4. Spending all day on a small boat with three other people necessitates attention to clear communication channels. The waves continually keep the boat in motion providing a challenge to manipulate the mouse and detail on the computer screen. In between there are many moments of quiet allowing for conversation and banter. It is in those moments you get to know one another better and forge strong relationships. This close community is evident among the crew on board. Such is the allure of sea life.

Sunny days

In anticipation of a trip to SE Alaska, I did a bit of research on what kind of weather to expect. Ketchikan is in a rain forest and noted for being the rainiest city in the United States with an average rainfall of 160 inches a year.  Since my arrival, I have enjoyed sunshine and calm seas. People have assured me how unusual this is and to expect a change. The forecast for tomorrow suggest the change will arrive. Seems to experience life at sea without a bout of inclement weather would not allow full appreciation of the grandeur we have had. I will take them both expecting there will be equal beauty in the rain and clouds.

I continue to be amazed at the majesty of the landscape.
I continue to be amazed at the majesty of the landscape.

4 Replies to “Bill Lindquist: The Small Boats, May 10, 2013”

  1. Hi Bill!
    Sounds like you are having a fantastic trip! How about driving the launch? Isn’t it hard? Did you end up with any holidays? By the way, the Plot Room looks so much more high tech than when I went in 2009.

    Happy Hydro!

    1. Hi Stacey,

      The learning curve is steep. Getting a good feeling for all that goes on, but have lots of respect for the folks that know it deeply enough to engage with it on a day to day basis.

      Yes, the launch didn’t always go where I wanted it to. I’d be fine if I only cared about getting from here to there, but needing to follow the line added precision which made it challenging.

      Lots of technology in the Plot Room – “helped” with night processing last night. Even with the more high tech, there were still glitches to problem solve. Part of the game.

      Take care,

  2. I should go back and read more about the CTDs but the process with the ‘pings’ reminds me so much of echolocation and bats. Serendipitously I guess we just read a book about bats with the class that I’m subbing for today. And yes I’m on a break, not neglecting my duties!

    1. Hi David,
      Thanks for the comment. Yes, as I understand it, there is simular science behind both – although different purposes. Each is based on sending out sound waves and listening for them to bounce back. Our ship is looking at data points that remain still (although the ship is continually moving) while the bat has to take in their movement along with a moving prey. Interesting connection.

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