August 1996
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OVERVIEW

Sample of Offshore Town Boundaries
Click to see the full size image.
This datalayer represents Offshore city and town boundaries for Massachusetts. The data are derived from 1:80,000 NOAA Charts and 1:24,000 USGS quadrangle maps of various dates. The coastline is the same as in the TOWNS_POLY and OUTLINE _POLY layers (1:100,000 USGS).

In ArcSDE are two layers - OFFSH80K_POLY and OFFSH80K_ARC.

ATTRIBUTES

The OFFSH80K_POLY attribute table contains the following items:
SEA 
 		0 and 1
TOWN_ID
 		Unique municipal identifier (from 1-351 Town ID List)

The OFFSH80K_ARC attribute table contains the following items:
SOURCE 
 		Source of arc and person digitizing. Arc source is either NOAA 1:80,000 charts or USGS 1:24,000 topographic quadrangle maps.
TYPE
 		Numeric code for source

Codes are as follows:
Type 
 		Source
0
 		UNKNOWN
1
 		V. ANTIL, DFWELE, NOAA CHARTS
2
 		V. ANTIL, DFWELE, USGS 1:24,000 TOPO MAPS
3
 		D. WEAVER, MassGIS, 1:24,000 USGS TOPO MAPS
4
 		N. MACGAFFEY, CZM, USGS 1:24,000 TOPO MAPS
5
 		MISC SOURCES

 

MAINTENANCE

MassGIS is maintaining the datalayer. No updates are planned. For more spatially-accurate coastline data see the Towns from Survey Points layer.

 

Last Updated 9/30/2008