Regulatory aspects
a vertical (surface waters) jurisdiction requires that the representative
cadastral boundary be 3 dimensional. This example is difficult to
understand and map and complex to manage with regard to the resulting institutional responsibilities.
Another mapping problem can be highlighted by examining the set
of demarcation lines that have been establislied by the Convention on
the lnternational Regulations for Preventing Collisions at Sea, 1972
(commonly called C()LREGS). COLREGS define boundaries across harbour
mouths and inlets for navigation purposes. If a vessel is landward of the
COLREGS line, it must adhere to the Inland Rules of Navigation established under the Inland Navigation Rules Act (33 USC 2001 et seq.).
Seaward of the ( OLREC.S line, vessels are subject to rules of navigation
established by the International Regulations for Preventing Collisions
at Sea, as amended (33 USC. § 1 601 et seq.). Historically, the COLREGS
lines have been established by drawing a line across a harbour mouth
on a paper nautical chart. In addition, geographic references that
position these lines are published in the US Pederal Register. However,
these references typically include no co-ordinates and, furthermore, often
reference ambulatory or ephemeral geographic or manmade features.
The georeferencing methods used to describe the location of the COLREGS
line are all too often insufficient for use within a digital mapping environment. For example, the following language is used to describe a
section of the COLREGS line running from Tybee Island to St. Simons
Island, Georgia. “A line drawn from the southern most extremity of
Savannah Beach on Tybee Island 235" true across Tybee Inlet to the
shore of Little Tybee Island south of the entrance to Buck Hammock
Creek” (USDOT/USCG, 1995).
As evidenced by these few examples, creating actual digital spatial
map layers for use m GIS and Electronic Nautical Charts (F.NC) is often
problematic. In many cases, the legal description of the boundaries may
not adequately describe the geography or it may be extremely complicated, requiring subjective interpretation. New legislation and regulations must take into consideration the state of mapping technology.
Ideally, the policy regime will list the bounding co-ordinates and metadata (e.g., datum) with enough precision to adequately create the spatial
data layer. Removing the ambiguities is a necessary component to
reduce uncertainty for resource analysis such as may be done in GIS or
for safe navigational uses in ENC applications.
The Ocean Planning Information System
This effort to outline the policy framework is part of an ongoing project
to develop an Internet-based ocean governance and management GIS
to facilitate the shift in the US from fragmented management of individual ocean resources to a more integrated, region-wide management
approach. The Ocean Planning Information System (OPIS) Web site
was developed utilising Environmental Systems Research Institutes
(ESRI®) MapObjects
TM Internet Map Server in conjunction with Visual
291
a vertical (surface waters) jurisdiction requires that the representative
cadastral boundary be 3 dimensional. This example is difficult to
understand and map and complex to manage with regard to the resulting institutional responsibilities.
Another mapping problem can be highlighted by examining the set
of demarcation lines that have been establislied by the Convention on
the lnternational Regulations for Preventing Collisions at Sea, 1972
(commonly called C()LREGS). COLREGS define boundaries across harbour
mouths and inlets for navigation purposes. If a vessel is landward of the
COLREGS line, it must adhere to the Inland Rules of Navigation established under the Inland Navigation Rules Act (33 USC 2001 et seq.).
Seaward of the ( OLREC.S line, vessels are subject to rules of navigation
established by the International Regulations for Preventing Collisions
at Sea, as amended (33 USC. § 1 601 et seq.). Historically, the COLREGS
lines have been established by drawing a line across a harbour mouth
on a paper nautical chart. In addition, geographic references that
position these lines are published in the US Pederal Register. However,
these references typically include no co-ordinates and, furthermore, often
reference ambulatory or ephemeral geographic or manmade features.
The georeferencing methods used to describe the location of the COLREGS
line are all too often insufficient for use within a digital mapping environment. For example, the following language is used to describe a
section of the COLREGS line running from Tybee Island to St. Simons
Island, Georgia. “A line drawn from the southern most extremity of
Savannah Beach on Tybee Island 235" true across Tybee Inlet to the
shore of Little Tybee Island south of the entrance to Buck Hammock
Creek” (USDOT/USCG, 1995).
As evidenced by these few examples, creating actual digital spatial
map layers for use m GIS and Electronic Nautical Charts (F.NC) is often
problematic. In many cases, the legal description of the boundaries may
not adequately describe the geography or it may be extremely complicated, requiring subjective interpretation. New legislation and regulations must take into consideration the state of mapping technology.
Ideally, the policy regime will list the bounding co-ordinates and metadata (e.g., datum) with enough precision to adequately create the spatial
data layer. Removing the ambiguities is a necessary component to
reduce uncertainty for resource analysis such as may be done in GIS or
for safe navigational uses in ENC applications.
The Ocean Planning Information System
This effort to outline the policy framework is part of an ongoing project
to develop an Internet-based ocean governance and management GIS
to facilitate the shift in the US from fragmented management of individual ocean resources to a more integrated, region-wide management
approach. The Ocean Planning Information System (OPIS) Web site
was developed utilising Environmental Systems Research Institutes
(ESRI®) MapObjects
TM Internet Map Server in conjunction with Visual
291