Click here to visit our FAQ about America's Historic Lakes Click here to return to the home page Click here to see our site map with links to historic sites on the lakes Click here to visit the Table of Contents for the 300+ pages on the site Click here to search the site Click here to learn about the use of images on the site Click here to contact us

The Online Resource for Historians, Educators, Students and Visitors since 1997
This is a graphics-intensive publication, to fully experience the site we recommend you have JavaScript enabled.

 

 
Guest Contributors...             Edwin R. Scollon

Diving Lake Champlain...
The Valcour Bay Research Project-VI (b)


VBRP's
Underwater Survey


VBRP/LCMM Diving Crew August 2000

In partnership with...

Accumulating sediments have long since covered and concealed the battle debris that settled to the floor of Valcour Bay.  Its flat, featureless surface provides no visible indication of what lies beneath. 

Land-based archaeological surveys typically involve the physical removal of large quantities of sediment to discover what lies in distinct areas of study.  This approach isn’t feasible with the study of a vast, underwater battleground like that at Valcour.  This is because the work of the VBRP divers is limited by their supply of compressed air and their visibility of the site.  At the 40’ plus depths that we’re working, a standard tank of compressed air lasts an average of 45 minutes.  Once the divers disturb the sediment, it soon becomes suspended in the water column and the distance they’re able to see is reduced to mere inches.  The VBRP team would need to develop an unconventional approach.

A vast array of weapons complimented the British and American fleets during this eighteenth century battle.  Among them were cannon, mortars, swivel guns, muskets, swords and bayonets.  By the battle’s end, many of these objects and large quantities of shot had sunk to the bottom of the bay.  Since these objects consist mainly of iron and other metals, submersible, hand-held metal detectors offered a cost-effective and efficient means of locating them.    The detectors are capable of locating metallic objects, buried under several feet of sediment.

The survey team’s principal investigators chose to rely on a thorough and systematic method to search the project’s 50’ grids.  They decided to employ the parallel-track search pattern; it’s an overlapping, back-and-forth pattern.  Search and rescue teams often refer to this method as “mowing the lawn”.  It provides thorough coverage when there’s the potential for locating targets anywhere within a search area.  Since the team didn’t know if other artifacts existed or where they would find them, this method was our best option for conducting the survey.

Now the challenge for the team’s principal investigators was to develop a means to deploy the parallel-track pattern within the 50’ grids.  On a good day, underwater visibility is only about 20’ in the bay; how could divers consistently and accurately find their way across the grid’s 50’ expanse?

The team found their answer with the PVC grid posts that they had used to form the grid system.  By cutting channels in the tops of the grid posts, attaching tape measures to them and using triangulation, the divers were able to precisely determine where each corner of the grids should lie.  They found that the thick layers of clay in the bay’s floor held the posts extremely well.  It didn’t seem to matter how much the diver’s pulled on the tape measures; the posts didn’t budge.  The solution was simple – more posts!

Once a grid is selected for survey.  A series of posts are placed at precise intervals along the grid’s north and south borders.  We refer to these posts as transect posts.  Lines are strung between corresponding posts on each side that guide the divers as they traverse the grid.  The posts and the lines form a physical model of the parallel-track pattern.  The system allows the divers to concentrate on their metal detection and prevents them from becoming disoriented.  As with the survey map, I won’t go into to the minute details of the system; but a schematic is posted below for those who wish to study it.  This is the same schematic we provide to new survey divers when introducing them to the survey’s methodology. 
       

Continued here: Survey Documentation

Back to the VBRP HOME PAGE

Other links about Valcour Island and the Battle of Valcour within
The Lake Champlain and Lake George Historical Site

The Battle of Lake Champlain:
The American Revolution on Lake Champlain

Download a copy of The Lake Champlain Maritime Museum's Official VBRP Cannon Raising Commemoration Program- Click HERE.
 

IMPORTANT NOTE: 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 prosecution.

*America's Historic Lakes is a favorite of educators around the world. You can feel confident that the material
on this site is accurate, well-researched, properly cited and presented.

Creative Commons License
America's Historic Lakes by James P. Millard and Guest Contributors is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

 Privacy Policy


James P. Millard
Post Office Box 262
South Hero, Vermont 05486-0262
contact@historiclakes.org

Terms of Service and Disclaimer of Liability

The historical information on this web site is provided as a public service by James P. Millard. I  have attempted to be as accurate as possible in my presentation of this historical material. However, I make no claims, guarantees or promises about the accuracy, currency, or completeness of the information provided. In no event shall the publisher; James P. Millard, be liable for any errors or omissions with respect to any information on this site. Material submitted by guest contributors and published on the site is the property of the contributor and may be removed at any time at my discretion or upon request of the contributor. This website occasionally provides links to sites of other organizations maintained by third parties. These links do not constitute an endorsement of the content, viewpoint, accuracy, opinions, policies, products, services, or accessibility of that website. Links to third-party websites are provided as a public service and convenience to users of our site; James P. Millard/America’s Historic Lakes does not control, endorse or recommend the content on sites we may link to. Once connected to another website, you are subject to the terms and conditions of that website.