Navigation, Is Where It’s At

Today on R/V Kilo Moana: Transit from Astoria Oregon to Axial Seamount. Mooring recoveries.

Leaving Astoria, Oregon
View from the bow:

View from the stern:
Since time immemorial navigation has mattered to mariners. The ability to know where you are within the worlds’ oceans is key to conducting science at sea and can save your life.

Sextant still available for navigation.

Navigation for ship operations
The R/V Kilo Moana has a magnetic compass and sextant for the unlikely event that all the electronic navigation systems fail but no one ever uses these as the ship has two Global Positioning System (GPS) receivers. These give the ship’s exact latitude and longitude (map locations on the earth’s surface) as well as speed and course. This information is displayed on electronic charts that show our location.

The ship also has a radar system (which sends an electromagnetic pulse out that is returned by hard surfaces) that incorporates the GPS data and allows the ship to keep an eye out for other hazards or ships in the area. Two gyroscopes help the dynamic positioning system and auto pilot to keep the ship on course. An electronic fathometer gives depth soundings of the ocean floor, another helpful navigation tool.

Electronic chart display of R/V Kilo Moana leaving Astoria.

The second mate had developed the voyage plan for the ship to follow before we even left the dock in Astoria. The ship’s GPS, auto-pilot, radar and other tools ensured we had an efficient and easy departure from the Oregon coast.

R/V Kilo Moana docked in Astoria, Oregon.

All large ships have an AIS (Automatic Identification System) which sends out the ships name, location, heading, speed, size and weight to all other ships in the area. This integrates with the radar to ensure the Kilo Moana and other vessels do not get too close to each other. The VHF radio also allows the captain to communicate with other ships about how they will avoid collisions.
It is good to know we have all this equipment to help the well trained crew get us on site safely before we send the underwater vehicles to the depths of the ocean to begin our research.

Second mate Luke Barker.

Navigation is necessary for the science we do too!
When we deploy ROV Jason, we use the ships GPS and dynamic positioning system to position the ship exactly where we want to lower Jason. Once in the water, Jason uses an Ultra Short Baseline (USBL – a modern SONAR) communication system with the ship to determine its location underwater and together with the ship’s GPS we get fairly good navigation. The precision depends on the depth, but at 1500 meters the USBL system can give us Jason’s location within about 5 meters of a site. This is very useful because with Jason’s high-powered lights we can view about 15-20 meters beyond the ROV at the bottom of the ocean. So, if there is a feature we are looking for, like a black smoker, we can usually find it fairly quickly.

All the science data and sample collection is logged with a description, date, time and location, so it can be analyzed when we get back to shore. Andra Bobbitt, Oregon State University, data analyst is on top of the science navigation, sample and instrument locations. Utilizing a Geographic Information System (GIS) before the expedition, she has loaded all the necessary files onto the key lap tops. The GIS is utilized throughout the expedition to track the vehicle dives, check data quality and organize data by location and time. Having navigation as accurate as possible makes a big difference in the quality of the science we can complete.

On this expedition, we are also using an Autonomous Underwater Vehicle (AUV) from the Monterey Bay Aquarium Research Institute (MBARI). There will be more about how this vehicle navigates in a blog post coming up called “This Is Not a Torpedo”.