Coast Survey improves access to data on thousands of wrecks and obstructions

Knowing the locations of shipwrecks and other obstructions has always been important for safe navigation ‒ but mariners are not the only people who want to know about wrecks. They are also important for marine archeology, recreational diving, salvage operations, and fishing, among other interests. Now, Coast Survey has improved our Wrecks and Obstructions Database, giving everyone easy access to new records to explore.

Web-based map of wrecks
Coast Survey’s wrecks and obstructions database provides info on thousands of wrecks.

Historically, Coast Survey has maintained two separate sources of information on wrecks. We recently combined the sources, bringing together information on nearly 20,000 wrecks and obstructions.


Coast Survey established the Automated Wreck and Obstruction Information System (AWOIS) database in 1981 to help estimate the level of effort required to investigate items during a planned hydrographic survey, but maritime users were also interested in AWOIS’ historical records. However, because the emphasis is on features that are most likely to pose a hazard to navigation, AWOIS has always had limitations. Most notably, AWOIS is not a comprehensive record and does not completely address every known or reported wreck. Additionally, for a number of reasons, AWOIS positions do not always agree with a charted position for a similar feature.


Coast Survey compiles NOAA’s electronic navigational charts (NOAA ENC®) from sources on features that are navigationally significant. As the official chart data used in electronic chart and display information systems (ECDIS), ENCs are the authoritative source of information about known or reported wrecks and are much more comprehensive than AWOIS. However, the features in an ENC typically lack the historic information and context provided by AWOIS.


Correcting for some overlap between the two source databases, Coast Survey’s new wrecks and obstructions database now contains information on about 13,000 wreck features and 6,000 obstructions. Wreck features from each original database are stored in separate layers but can be displayed together. Users may also choose a background map from several options.

The new database also offers users additional data formats from which to choose. Historically, shipwreck data in AWOIS was available in Adobe PDF and as Microsoft Access Database (MDB) format. More recently, KML/KMZ files replaced PDF and MDB formats, making it easier for public users to view AWOIS data, by using freely available software such as Google Maps or Google Earth. Now, in addition to KML/KMZ and Microsoft Excel formats for general users, Coast Survey provides the data in ArcGIS REST services and OGC WMS services, for use in GIS software programs or web-based map mashup sites.

Coast Survey unveils easier access to wreck information

By Lucy Hick, physical scientist, Hydrographic Surveys Division

Maintaining documentation for features depicted on nautical charts is more complicated than you probably imagine. For instance, Coast Survey maintains information on more than 10,000 submerged wrecks and obstructions in U.S. coastal waters – and it just got easier for the public to access that free information.

Coast Survey uses our Automated Wreck and Obstruction Information System (AWOIS) to help plan hydrographic survey operations and to catalog the many reported wrecks and obstructions considered navigational hazards within U.S. coastal waters. The public also has access to this rich information source. Marine archaeologists and historians, fishermen, divers, salvage operators, and others in the marine community find AWOIS valuable as an historical record of selected wrecks and obstructions.

Information contained in the database includes latitude and longitude of each feature, along with brief historic and descriptive details. Until recently, that information was available for download in Microsoft Access MDB and Adobe PDF format. However, these formats were difficult to search.

As of today, AWOIS information will no longer be available in MDB or PDF format. Instead, users can download AWOIS files in the more useful Google Earth Keyhole Markup Language (KML) format. KML is an XML grammar and file format for modeling and storing geographic features such as points, lines, images, polygons, and models for display in Google Earth, Google Maps, and other applications. (KML is an international standard, maintained by Open Geospatial Consortium, Inc.)

AWOIS record
AWOIS record

Once you download an AWOIS file, you can open that file directly in a mapping application, such as Google Earth or Google Maps. You can then navigate directly to your area of interest and obtain information about individual features. Clicking on any AWOIS item will bring up additional information, such feature type, position, and history.

I’ve provided an example, below, of an AWOIS file opened in Google Earth. On the right is an example of the information that will be displayed by clicking on a AWOIS item.

Questions? Just ask them in the comments section or send an email to Coast Survey’s Hydrographic Surveys Division at

AWOIS in Google Earth
AWOIS in Google Earth