By Mass Communication Specialist 2nd Class Lily Daniels, U.S. Naval Forces Southern Command/U.S. 4th Fleet Public Affairs

FORTALEZA, Brazil (NNS) -- Surveyors from the Naval Oceanographic Office (NAVOCEANO) demonstrated shallow water survey techniques to naval hydrographic officers from the Brazilian Naval Hydrographic Center March 26-27 in Fortaleza, Brazil.

The techniques focused on locating subsurface wrecks and other navigational hazards in an area near the port of Fortaleza.

The surveyors launched one of the two hydrographic survey launches (HSL) that are maintained aboard the Military Sealift Command naval oceanographic survey ship USNS Henson (T-AGS 63). The HSL is a 34-foot long vessel that is equipped with systems similar to the Henson; however, they're specialized for shallow water surveys. The equipment includes sidescan sonar, multibeam sonar, sound velocity sensor and navigation systems.

The HSL is used to conduct military surveys in shallow water around ports, in-between islands and around open coastal areas with complex and/or poorly charted waters.

"One of the main uses of the HSL is to determine hazards to navigation on the ocean floor and clear a port, especially after an event like the earthquake in Haiti, so that ships carrying relief supplies can safely navigate to the pier," said Henry Charry, lead hydrographer from NAVOCEANO. "Ships can't see submerged hazards when transiting into port, so it's important these hazards are discovered to ensure navigation charts are appropriately updated and marked."

The surveyors used the equipment to determine if hazards such as anchors, reefs, islands, seamounts or shipwrecks were on the ocean floor.

"When we identify a hazard like a wreck or shoal we go over it with the sidescan sonar. It can produce an image so detailed that we can see the sand ripples on the sea floor," said Melody van der Linde, an oceanographer from NAVOCEANO. "We found an anchor the first day of surveying."

The second day of surveying revealed two submerged hazards.

"One is in a different position than we thought and the other is not on our charts," said Lt. Felipe Marques from the Brazilian Naval Hydro-oceanographic ship Taurus (H-36).

Members of NAVOCEANO and Henson are currently engaged in the first ever Oceanographic-Southern Partnership Station (O-SPS) with the Brazilian Navy. O-SPS is an engagement focused on oceanographic surveying and the exchange of information between subject matter experts from partnering navies within the U.S. Southern Command Area of Responsibility.

NAVOCEANO, the largest subordinate of the Naval Meteorology and Oceanography Command, collects and analyzes global ocean and littoral data to provide specialized, operationally significant products and services for military and civilian, national and international customers.

"We found similarities in software and surveying techniques. However, we currently don't have an HSL on our ships. Usually, when we go out for these types of surveys we have to install the equipment on a smaller vessel. We don't have permanent equipment on the smaller boats," said Marques.

Southern Partnership Station is a recurring deployment conducted by Commander, U.S. Naval Forces Southern Command (COMUSNAVSO) and U.S. 4th Fleet with a variety of different objectives.

COMUSNAVSO is the naval component command for U.S. Southern Command and is responsible for all naval personnel and assets in its area of responsibility. COMUSNAVSO conducts a variety of missions in support of the Maritime Strategy, including theater security cooperation, relationship building, humanitarian assistance and disaster response, community relations and counter-illicit trafficking operations.