Proceedings Of The Marine

SUM 2015

Proceedings magazine is a communication tool for the Coast Guard's Marine Safety & Security Council. Each quarterly magazine focuses on a specific theme of interest to the marine industry.

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11 Summer 2015 Proceedings The future of navigation will be an interesting combination of doing the same things better and doing things that were never before possible. For example, those things that made a chart "good" in 1800 will still be true going forward. How- ever, we no longer use charts alone. Gone are the days of paper plotting, tide tables, maneuvering boards, the weather fax, and the U.S. Coast Pilot volume on the shelf. But we still need all the same information. In fact, we need more infor- mation, much more frequently. Navigation Challenges Today, ships are larger, with deeper drafts, which means there are smaller margins under keel, alongside, and over- head in many ports and waterways. So pilots in most ports now carry precise navigation systems that display the lat- est channel conditions and other port-specifc information. Additionally, U.S. port infrastructure often includes tide and current gauges and real-time bridge air gap sensors to allow pilots and ship captains to make decisions about cargo loading and timing ship movements. But this is just the beginning. Mariners also need a detailed understanding of the physical environment — the sea and atmosphere — to support navi- gation decisions. Fortunately, we have weather models that drive detailed coastal sea state predictions as well as super- computers with hydrodynamic models that predict a full three-dimensional feld, including currents, temperature, and salinity, as well as water levels, over broad coastal areas. We also have multibeam surveys that create high-resolu- tion seafoor models, high-frequency radars that measure surface current in coastal areas, and a network of weather buoys that measure offshore waves and wind. So, the good news is these tools exist. The trouble is, most are not yet available at the point of decision, and, more importantly, they are not being integrated into an action- able context. From the mariner's point of view, the tools just provide information. To be useful, the information must support decisions in a specifc context. Environmental Intelligence Fortunately, the National Oceanic and Atmospheric Admin- istration (NOAA) is bringing together the best science, the most relevant observations, and the most sophisticated atmospheric and hydrodynamic modeling and prediction information across a wide variety of disciplines, to support these decisions. One challenge, though, is that public policy is lagging behind technology. For example, in the U.S., most ships Future Navigation Building upon navigation's history. by CAptAin Shep SMith Deputy Hydrographer Offce of Coast Survey National Oceanic and Atmospheric Administration Federal Agency Involvement Imagine a Ship Getting Underway in 2025 Twenty-four hours before leaving port, your ship's manage- ment team is making fnal decisions on loading and planning the departure from port. Your voyage management system downloads the updated environmental intelligence report, which includes weather and hydrodynamic predictions and the latest channel condition survey. At the time of your planned departure, persistent northeast winds are predicted to drive two feet of extra water into the bay, but heavy river outfow means the water will be lower salinity; however, the incoming tide will drive a salt wedge into the harbor toward the end of the high tide, raising water density by 2 percent. The swell at the sea buoy will have diminished to the point where it will have negligible efect on the ship. Based on this information, you delay your departure by 20 minutes to take advantage of peak salinity and higher tides, and you load the ship an extra two feet. You adjust your planned track to follow the channel centerline in an area that the channel condition survey shows shoaling on the left outside quarter. Your under-keel clearance risk management system calculates the risk of grounding at .008 percent, which meets your underwriters' and captain of the port risk criteria.

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