This website provides information about the background and limitations of the Wrecks and Obstructions Database.
In addition, details of the attributes of the wrecks and obstructions data sets are provided.
Background and Limitations
Historically, NOAA has maintained two separate sources of information on wrecks and obstructions.
- The Automated Wreck and Obstruction Information System (AWOIS) database was established in 1981 to help estimate the level of effort required for investigating items within the limits of
a planned hydrographic survey. However, because of the emphasis is on features which are most likely to pose a hazard to navigation, AWOIS has 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 may not agree with a charted position for a similar feature.
- NOAA ENC®s (electronic navigational charts), first developed in 1997, have been compiled from authoritative source on features (including shipwrecks) that are navigationally significant, and
they provide 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 lack the historic information and context that is provided by AWOIS.
Each record has a series of attributes, which provides information about the wreck or
obstruction. These attributes are listed below, along with their descriptions.
|Unique numerical record identifier (East Coast: 1 - 49,999, West Coast: 50,000 +).
|Name of the vessel (if known) or the terms UNKNOWN or OBSTRUCTION.
|Describes the physical characteristics of the feature.
||Wreck - Submerged, dangerous Wreck – Submerged, nondangerous Wreck - Visible Not Charted Obstruction - Covers/uncovers
|Latitude in decimal degrees using the North American Datum of 1983 (NAD83).
|Longitude in decimal degrees using the North American Datum of 1983 (NAD83).
|An indicator of the relative positional quality of the feature.
A description of positional accuracy categories is provided below.
|An indicator of the method in which the position was derived from the source document. Options include:
Scaled: scaled from a
hard copy or from a digital image,
Direct: Transcribed directly as reported in the source document.
|Actual least depth or wire drag cleared depth over a feature that has been determined
by hydrographic or wire drag survey methods.
ENC Depths are always reported in meters.
For AWOIS items, the units are indicated by the attribute Depth Units.
|Indicates the units in which the least depth over the feature has been determined.
||Feet and tenths
Fathoms and tenths
Meters and tenths
Wire-drag clearance, feet
Wire-drag clearance, fathoms
|The year in which the vessel was sunk, if known or the term None if unknown.
|Memo field that contains additional information about the feature.
For AWOIS features, entries in this category may be or unreliable. Common codes in AWOIS histories include hydrographic survey registry numbers
(e.g., H-9872/79), shoreline manuscript registry numbers (e.g., TP-00278), miscellaneous document numbers (e.g., CL980/76 and BP100234),
and U.S. Coast Guard Local Notices to Mariners (LNM).
Any positions in the History memo field are for reference purposes only and will have generally been superseded
by the positions in the Latitude and Longitude fields.
|OPR-B301-RU-07-- 36 ft wreck; This wreck was submitted as a DTON by the field party on April 26th, 2004. This wreck is shown on chart 13223,
38th Edition, April 2005, and has been applied to the continual maintenance raster dated August 29th, 2006 (RES 10/26/07).
(ENC Wrecks Only)
|Indication of the reliability of the value of sounding over the wreck.
least depth known
value reported (not confirmed)
|Water Level Effect
(ENC Wrecks Only)
|Indicates the effect of the surrounding water on the wreck.
always under water/submerged
covers and uncovers
Positional Accuracy (AWOIS only)
- High: A high quality position originating from a survey source or whenever there is a high level of
confidence that the wreck or obstruction may be relocated without unreasonable difficulty. Although
most positions in this category originate with NOS surveys, other sources may qualify, as long as the
originating authority has the capability to do high quality work. Authorities such as the U.S. Army Corps
of Engineers and private surveyors are selected examples.
- Med: A probable high quality position, such as that originating with a survey but lacking supporting
documentation. Positions originating from non-agency sources may also be in this category if the
location is tightly controlled by adjacent features such as pier lines or fixed aids to navigation. A report
that the wreck or obstruction has been actually located by the Coast Guard or Corps of Engineers will
usually qualify a position for this category. In some cases, the item may be charted with an approximate
position (PA) notation.
- Low: A position of questionable or unverified quality. Most reports from Local Notice to Mariners
and private observers are of this type. If the reported position is expressed a range and bearing from
an identifiable fixed feature and is near shore relative to the position fixing method, it will probably
be included in this category. If the position fixing method is unknown, it is assumed to be visual. The
nautical chart may indicate an approximate position (PA) for this item.
- Poor: A position of doubtful quality usually referenced to some general shoreline feature or portion of
shoreline. The nautical chart may indicate an approximate position (PA) or a position doubtful (PD) for
AWOIS Acronyms and Abbreviations
NOAA has provided a list of acronyms and abbreviations which are commonly used in the AWOIS records.
Wrecks and Obstructions Database Inquiries:
For any questions, comments, or concerns related to the Wrecks and Obstructions Database, please submit an inquiry