Wrecks and Obstructions

  In 1981, NOAA’s National Ocean Service implemented the Automated Wrecks and Obstructions Information System (AWOIS) to store data on reported wrecks and obstructions that are considered to be navigational hazards within U.S. coastal waters. Traditionally, if more information were needed about a specific wreck or obstruction, NOAA’s Office of Coast Survey would use vessels previously scheduled for surveying that area to conduct further investigations. The results of these investigations were then added to the permanent history of the feature in AWOIS. The Wrecks and Obstructions data set within uses the information found in AWOIS to create a downloadable data set.   So why should ocean planners pay attention to the Wrecks and Obstructions data set?

  1. This data set has more information than a nautical chart. Nautical charts include hazards that are specifically a threat to navigation, whereas the Wrecks and Obstructions data set includes additional hazards and may therefore be used for other purposes beyond navigation. It includes the ship name, length, type, and possibly even how the ship sank. For some of the entries, users may even find a time stamp and photo.
  2. New wrecks do not instantly show up in AWOIS or the data set. It’s always important to note that databases such as AWOIS are not instantaneous. Wrecks are regularly reported to NOAA’s Office of Coast Survey by the U.S. Coast Guard; however, reports aren’t added to AWOIS until they’ve been investigated further through additional surveys. Then the data must be updated inside of the data set. A reported wreck that presents a navigational hazard, usually in shallower depths, will most likely show up in the nautical chart and, if the position is questionable, will include annotations to let the user know.
  3. This data set helps to inform where fishing and diving activities may occur. Nautical charts do not provide information on fishing and diving spots, but these areas can be implied from the Wrecks and Obstructions data set. This data set also includes things that are not wrecks or traditional obstructions, such as net hangs, old pilings, or even large pieces of piers that were carried out to sea in a storm and sank. These items often turn into artificial reefs. It’s important for planners to take note of these spots to avoid conflicts and to make this information available to those scouting potential fishing or diving spots.

Quick Caveats. It’s important to note that the data in are updated on a regular cycle, not whenever AWOIS is updated. AWOIS and nautical charts differ more than in the amount of information they provide for a specific wreck. AWOIS only includes wrecks that have been further investigated, and nautical charts only include wrecks that are a threat to navigation. So wrecks could be shown on the nautical chart that aren’t in AWOIS, and therefore are not in, and vice versa, or the positions might not match. Also, because of recent advancements in electronic navigational charts, wrecks and obstructions information is no longer added to AWOIS but is added straight into the electronic navigational chart. The Marine Cadastre data set is currently up to date, and when the time comes to update it again, it will pull from the most recent, complete database. Five categories depict the accuracy of the position of the wreck or obstruction: 1) high position quality means the wreck or obstruction could be located again without unreasonable difficulty; 2) medium position quality means the wreck or obstruction is likely a high position quality but lacks supporting documentation; 3) low position quality means the wreck or obstruction is either in a place that is not easily located again or has unverified quality; 4) poor position quality is given to those wrecks and obstructions in a doubtful quality (this designation usually refers to some general shoreline feature or portion of shoreline); and lastly, 5) unknown position quality simply means the wreck or obstruction was not found when the survey ship searched for additional information. For more information on AWOIS, go to the user guide.

Data-Source Experts
Kyle Ward, Navigation Manager Southeast, Office of Coast Survey, NOAA
Lucy Hick, Physical Scientist, Hydrographic Surveys Division, Office of Coast Survey, NOAA

For questions, please contact