Navy Oceanographic Research Ship (AGOR) Numeric Listing
Navy Survey Ship (AGS) Numeric Listing
Hydrographic - Oceanographic
Personal View
Hydrography is an old discipline that goes back to the first time someone recorded information to pass to the next person who might sail (row, paddle, or whatever) in the same area. In fact, some of us who came from an oceanographic viewpoint thought it was pretty stuffy. My answer now is a somewhat mushy "yes and no" because I've gained more respect for hydrography while still being somewhat impatient with some unnecessary clinging to tradition.
The old dictionary definition of "hydrography" really includes "oceanography" yet I don't think it really evolved that way. "Hydrography" sort of got pushed into a niche during the rise of "oceanography," particularly as it got very popular in the 1960s. In effect, "hydrography" might be considered "oceanography for the mariner" while "oceanography" sort of includes "hydrography" as seen by the scientist or engineer.
Here is an example and another term, "bathymetry," which is and is not "hydrography." Bathymetry is sort of an oceanographer's hydrography. As a bathymetrist my mission was to describe as best as possible the actual shape of the terrain under sea water. It was to produce a topographic map ("chart" in nautical usage) of the wet land. This is necessary for scientific or engineering related to acoustic ray path or laying cable. This may be entirely unnecessary for the mariner who simply wants to avoid disastrous contact of his hull with that land. As a bathymetrist I produced contour charts just as are seen for land features. As a hydrographer I'd be more likely to produce "depth curves" -- similar looking lines, but with no pretense of really portraying the lay of the "land." They may sort of do that, but their real purpose is to show a limit of the area in which lesser depths may be found. A 10 fathom depth curve is not a 10 fathom contour -- it essentially says "outside this line you should not find any "hard stuff" (land) less than 9.999 fathoms below the water's datum (A whole issue in itself!). If you know the state of the tide and your lowest point in the water, you can use these curves to stay away from hard, high spots that do nasty things.
Hydrography also includes things ashore and afloat that help know where one might be in relation to those curves and representative depths. Hydrographers note things like lights, buoys, landmarks and such that an oceanographer might ignore except when actually navigating. An oceanographer may use them, but not necessarily record them.
Many of these ships did work before oceanography and even real bathymetry was well established in the Navy. Those came largely as a result of the need to understand the total environment for Antisubmarine Warfare (ASW) and reached their peak with the very real Soviet submarine threat. A personal concern and bit of sadness is that with a lessening of the deep blue threat is a sharp lessening of support for deep ocean bathymetry and oceanography. These things are very expensive and taxpayers are not willing to fork over the huge sums just to know the detailed shape of a piece of deep mountain range. New techniques help gain some knowledge, but without the threat there is little interest or need to go out and map those great seamounts and ranges. We will know more about the back side of the Moon and Mars that many of those. Some of us had the interesting experience of finding and then mapping a new mountain, whole group or even small range where the charts were pretty much blank. That experience is going to be less common -- not because we know so much more, but because the reason for doing so is now "just science."
By the way, the nation's time keeper is under the Oceanographer of the Navy and HQ is at the beautiful old Naval Observatory in Washington. Why? Time was absolutely critical to navigation. It still is. A huge effort in the days of sail was the search for an accurate seagoing clock. It was the only way to determine longitude. Empires depended on it. It perhaps illustrates why knowledge of the deep oceans was so dependent on a military imperative. Despite lots of idealistic talk, people in general really are not simply so curious that they put large investments into knowing things.
Specialized to Hydrographic & Oceanographic Site Links
General maritime links are on their own page.
Australian Hydrographic Office
International Hydrographic Organization (IHO)
National Association of Marine Laboratories (NAML) with links to many individual labs. Here are some specific labs, whether or not NAML: Scripps Institution of Oceanography, Woods Hole Oceanographic Institution
Ocean Information Center (OCEANIC); Graduate College of Marine Studies, University of Delaware
United States: We really split things up. The Oceanographer of the Navy has "oceanography," but the navigational charting (hydrography) is under the control of the National Imagery and Mapping Agency -- for DoD. But then our civiliana, territorial waters are the responsibility of NOAA, a DoCommerce agency. So, if it is defense or outside territorial waters it is either Navy or NIMA (I won't even try to explain that history even if I lived through it!), but if it is in territorial waters (including lots of Pacific islands) it is NOAA. NIMA has a consolidated Marine Navigation page. By the way, piracy is not dead -- read some of the Anti-Shipping Activity Messages.
University of Georgia's Department of Marine Sciences and Sapelo Island where I spent some very interesting and pleasant times that included a first taste of oceanography aboard the R/V Kit Jones. It really is a "Golden Isle."
Navy Oceanographic Research Ship (AGOR) Numeric Listing
Navy Survey Ship (AGS) Numeric Listing
Copyright © 1999 by Ramon G. Jackson
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