NOAA hydrographic survey vessels are valuable assets for search and rescue operations, as experienced crews use their knowledge of tides and ocean currents to develop science-based search patterns. Last month, two divers found out just how valuable NOAA’s expertise can be. — DF
Report submitted by Ensign Brittany Anderson, NOAA Ship Thomas Jefferson
On the morning of August 26, 2012, NOAA Ship Thomas Jefferson was conducting routine hydrographic survey operations south of Block Island. At 0904 hours, a distress call was made on the very high frequency (VHF) radio to the Coast Guard Station. The caller reported two divers lost in the water at Southwest Ledge, a popular recreational point off Block Island. The coordinates were a mere seconds north of the Thomas Jefferson.
A third diver was on a private boat with no VHF radio. He hailed the fishing boat Captain Ron, and that boat called the U.S. Coast Guard, Sector Long Island Sound. The third diver continually returned to the water to search for the two missing divers.
At 0907, the Coast Guard reported via VHF that one of their vessels was on its way, but was 25 minutes out. Cmdr. Larry Krepp, commanding officer of the NOAA Ship Thomas Jefferson, contacted the Coast Guard and informed them of our location and ability to assist in the search for the missing divers. Numerous additional lookouts were called to the bridge to search all points off the ship. At 0908 our ship stopped logging hydrographic survey data, and we retrieved our moving vessel profiler from the water. We calculated the current set and drift from Southwest Ledge and began search lines in the vicinity of the divers’ expected location.
The divers’ initial location is indicated at Southwest Ledge. The red arrows indicate Thomas Jefferson’s search lines, and the red circle shows where the divers were retrieved.
Ensign Brittany Anderson, Ensign Anthony Klemm, Ensign Andrew Clos, Lt. Cmdr. Denise Gruccio, and Cmdr. Lawrence Krepp kept a heavy lookout on all sides. Chief hydrographic survey technician Peter Lewit and physical scientist James Miller updated the expected location of the divers based on current set and drift calculations. Able seaman Tom Bascom was at the helm, steering the course to search for the individuals. At approximately 0930, the Coast Guard rescue vessel arrived on scene and made contact with the third diver. At 0952, Lt. Cmdr. Gruccio spotted the two divers broad off the port beam at a bearing of 282° PGC (per gyrocompass.) We reported the position and distance to the Coast Guard rescue boat on scene; they promptly followed our pointing and bearing to the divers. They safely retrieved the two divers at 0955.
After receiving word from the Coast Guard that the divers were safe and our services were no longer needed, we came about to our survey course. We continued our hydrographic survey operations, relieved and pleased that our training and hydrographic knowledge gave us the ability to find the divers quickly and safely.
The U.S. Coast Guard picked up the two divers, after they were found by NOAA Ship Thomas Jefferson. (Photo by ENS Brittany Anderson.)
NOAA Ship Thomas Jefferson is one of the most technologically advanced hydrographic survey vessels in the world. Equipped with high-resolution seafloor echo sounders, the 208-ft. Thomas Jefferson and its 36-person crew maps the seafloor in support of Coast Survey’s nautical charting mission.
NOAA Ship Thomas Jefferson
“But more wonderful than the lore of old men and the lore of books is the secret lore of ocean.”
H.P. Lovecraft, author
The Rainier crew sees the morning fog start to lift from the ship’s anchorage site.
Working on a NOAA ship, discovering ocean secrets, is an enviable job as well as an essential one. One can’t help but envy the scientists and crew of NOAA Ship Rainier as they conduct their hydrographic survey around the Shumagin Islands this month. Their pictures are hauntingly beautiful. And their mission in the midst of the beauty will help to protect the lives of Alaskan fishermen.
This area is experiencing increasing fishing vessel traffic, and the Alaska Fisheries Development Foundation has asked NOAA’s Office of Coast Survey to improve charts used by longline and pot fisheries. Much of the project area has never been adequately surveyed, and large portions of NOAA Chart 16540 have no soundings at all. Fishing vessels need to know ocean depths, and the presence of underwater rocks and other hazards, to stay safe during operations.
In response to the need of local fisheries, Coast Survey will use Rainier’s modern multibeam echo sounder bathymetry to create accurate charts. In addition to acquiring new bathymetry data, Rainier is verifying 2009 data acquired by airborne bathymetric LiDAR from near shore areas around the islands.
Rainier’s survey boats set out at first light to take advantage of a “negative tide” to map the shoreline and its many rocks and hazards. Many rocks that would lie just below the surface during a normal tide range will be exposed and visible during a negative tide.
Rainier is currently surveying the areas outlined in blue. Note the lack of charted soundings (water depth measurements) in the survey area.
UNOLS Research Vessel Atlantis, operated by the Woods Hole Oceanographic Institution, transits to a joint Canada-U.S. survey location in the North Atlantic.
The U.S. and Canada have been surveying in the northern Atlantic Ocean this summer, gathering data to support both countries’ territorial claims under the United Nations Convention on the Law of the Sea (UNCLOS). The survey project started on August 15, and the ship is scheduled to return to Woods Hole, Massachusetts, on September 10.
Lt. Briana Welton, a NOAA Corps officer, is representing the Office of Coast Survey and the NOAA-University of New Hampshire Joint Hydrographic Center, as the team of eight Canadian and U.S. hydrographers and geologists work onboard the University-National Oceanographic Laboratory System’s Research Vessel Atlantis. (The Woods Hole Oceanographic Institution operates the Atlantis).
This image shows the multibeam sonar coverage of 116,600 square kilometers, as of noon 4 September 2012, overlaid on a Canadian nautical chart. (Red dashed line shows where the foot of the slope was originally thought to be located.)
The survey team has been mapping the North Atlantic Continental Slope on the Canadian side of the Hague Line, acquiring multibeam, sub-bottom profiler, magnetic, and gravity data. (Check out Where is Atlantis Now?, for a great map of their cruise.)
The national effort to establish the full extent of the continental shelf is vital to the U.S. economy, as the ocean shelf has energy and mineral resources likely worth many billions of dollars. The process for extending the shelf is outlined by the U.S. Extended Continental Shelf Project:
Under international law, as reflected in the Convention on the Law of the Sea, every coastal State [country] automatically has a continental shelf out to 200 nautical miles (nm) from its coastal baselines, or out to a maritime boundary with another coastal State. However, a coastal State may define a continental shelf beyond 200 nm (called an extended continental shelf), if it meets the criteria outlined in Article 76 of the Convention. The process requires the collection and analysis of data that documents the natural prolongation of the continental landmass beyond 200 nm as determined by the formulae and limit lines in Article 76.
NOAA is one of the U.S. agencies leading the effort to collect the data that would allow our Nation to extend the shelf.
The crew of RV Atlantis deploys equipment to measure the conductivity, temperature and density of water, to correct for oceanographic characteristics when measuring water depths with sonar.