Resource for Historians, Educators, Students and Visitors since 1997
This is a
graphics-intensive publication, to fully experience the site we
Edwin R. Scollon
Diving Lake Champlain...
The Valcour Bay Research Project-VI (a)
Mapping of Valcour Bay
Valcour Bay, Lake Champlain
Photo Credit: Doug and Mark Harwood
we’ve discussed in the previous pages, the locations of the battle’s
artifacts have as much educational potential as the artifacts themselves.
Preserving that potential is the primary concern of the U.S. Navy and New
York State Museum officials that oversee the project. The team would have
to meet a series of archeological requirements before any consideration
would be given to the artifacts’ removal from the bay. Developing a means
to accurately record the placement of the artifact scatter was the team’s
Mapping an underwater archeological site
involves conditions and challenges not inherent to those of land sites.
Conventional surveying equipment and global position systems (GPS) won’t
function in an underwater environment. Limited underwater visibility and
the absence of distinct landmarks in the bay further complicate the issue
and raised concerns of the survey divers becoming disoriented. The team’s
response was to develop an artificial system of landmarks from which the
divers could plot artifact locations and find their way about the site.
The survey team
developed a system that relies on the use of a series of posts embedded
into the bay’s floor. The posts are constructed from three-foot sections
of PVC pipe. PVC (poly vinyl chloride) is a plastic material commonly
used in household plumbing. The material is durable, non-soluble and
non-corrosive and poses no threat to the bay’s ecosystem. It’s also white
in color, making it highly discernable against the grayish-brown sediments
of the bay’s floor.
on the thumbnail images to see a large photo.
During the 2001 survey, the team had 25
divers complete 154 dives in two weeks. We completed twelve survey
grids during that time. The team soon moved away from the anchor
pad that we had also used as an entry and exit point.
Here, LCMM diver, Pierre LaRocque, pulls
the buoy to the pre-selected grid posts and assists Mr. Bennett with
obtaining his DGPS data.
This image was taken just after 1999's
Hurricane Floyd paid the Champlain Valley a visit. The storm's
power pushed heavy currents and massive amounts of debris through
the bay. The grid posts were some of the few objects that offered
any kind of resistance to the flow of water and debris. The team
spent several days removing the tumbleweed from the posts.
The white grid posts stand out clearly
against the dark sediment.
The grid posts came to the rescue
again. We saved precious dive time by stringing guide lines onto
the grid posts that rested between the anchor pad and the advancing
survey sites. In effect, they took the "navigation" out of our
navigating. They also provided a measure of safety by assisting the
divers in making their entry and exits from a common predetermined
PVC transect, grid and anomaly posts.
The channels in the grid posts are cut to secure measuring tapes and
Submersible compasses are often as
valuable to divers as their dive computers and their depth and air
pressure gauges. They're a standard piece of equipment
that's commonly included on gauge consoles like this one.
Tools of the trade. Clockwise from top
left: gauge console that features a submersible compass;
carabineer to secure equipment to the diver's vest; clipboard, with
attached mechanical pencils and a waterproof sheet of Mylar; PVC
transect, grid, and anomaly posts; 50' and 100' tape measures;
spring clips to attach lines and tapes to the PVC posts; and a
"goody bag" in which drivers typically carry their gear.
The team decided to
reduce the survey site and their efforts into manageable 50’ squares, or
grids. The PVC posts, or grid posts as we call them, are used to form the
corners of the grids and the skeleton of the grid system. Because they’re
placed at precise 50’ intervals, they become landmarks from which
artifacts locations can be accurately plotted and from which the survey
map can be drawn.
Since divers navigate
underwater through the use of submersible compasses, the grid posts and
resulting grid system are aligned with magnetic north. This alignment
assists divers in navigating about the site. Once divers locate a grid
post they need only proceed directly north, south, east or west to find
their way to another. A unique designation is also written on each grid
post so the divers can determine exactly where they are within the site.
The system mimics the
geographical system of latitude and longitude, from which precise points
can be recorded on the map and relocated on the lake floor. The
intricacies of the system are beyond the scope of this site and probably
the interest of most of its viewers; but a model of the survey site and
map is posted below.
survey divers encounter battle artifacts their precise location within the
site is plotted upon a master survey map. The result is a permanent
record of that will be available for researchers to study. From the
artifact scatter they may be able to glean information unavailable from
Continued here: VBRP's Underwater Survey
Back to the VBRP HOME PAGE
Artifacts on the bottom of the lake are the
property of the People of the States of New York and/or Vermont by law. It
is illegal to remove or damage them under State Law(s) without the
appropriate clearances and permits. Removing them and transferring them
across state lines violates Federal law & makes one liable to Federal
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