Something completely different

The St Mary’s River Watershed Association has asked IMH to lay six to eight mounds of hollow concrete reef balls as part of their oyster restoration project.  Each mound would comprise 31 to 37 balls.  Each  ball weighs about 350 pounds, so that makes approximately 42 tons to move.  We can handle the balls easily with Roper‘s davit, one at a time.  We probably can carry and deploy six or more balls on a trip, so the whole job would take perhaps 40 trips over two weeks — mostly weekdays, some weekends, preferably when the weather is too rough to dive the four lower Potomac shipwreck sites on the current schedule.  We should start on Monday 9 Sep when the Association’s director is available to show us how to do it.

If you would like to participate please click the “contact” button at the top right corner of this webpage.

IMH fieldwork schedule, 2013

2013 fieldwork schedule:
February & March —
  sidescan sonar training on weekends
  boat maintenance on weekdays
April —
  dive & map sites in Potomac River or
    Chesapeake Bay on first 2 weekends
  boat hull and engine work after 11 April
May —
  boat hull and engine work until 9 May
  underway 11 May for Georgia and Florida
  scan sites in Georgia
  arrive St Augustine FL on 25 May
June —
  LAMP field school in FL
  17th century site in MD
July & half August —
  field reconnaissance, Florida
half August —
  scan sites in Georgia
  arrive Tall Timbers MD on 25 August
September through mid November —
  map sites at Quantico, Mount Vernon,
    and Aquia, Virginia

For more information email

Chesapeake and Delaware reconnaisance, autumn 2012

During September and October 2012, IMH plans to continue an underwater reconnaissance in the Delaware River for several American warships and one British warship that were sunk in 1777.  Our work will support the efforts of Andrew Doria – The First Salute, Inc., to build a replica of the brigantine Andrew Doria, one of the vessels lost.  She was one of the first four vessels purchased by Congress for the Continental Navy in 1775.  The project will be coordinated with the State of New Jersey and the U.S. Naval History and Heritage Command.

On our way to the Delaware and back we will also reconnoiter 88 possible shipwrecks in the Chesapeake Bay for the Maryland Historical Trust (MHT).  Five of the sites are in the Potomac, and 83 are in the Bay.  We have scanned many of them in prior transits, but have only dived a few.  Many of them may never have been dived.  The sites lie along 147 miles of transit from Tall Timbers MD to the C&D Canal.  Site data will be reported to MHT and nobody else.

Scanning will employ IMH’s hard-mounted sidescan sonar.  When conditions and manpower allow, we will also use a Marine Sonic Technologies “Splash Proof PC” sonar on loan from the National Park Service.  The Marine Magnetics “Explorer” magnetometer that was used in the first part of the project in April and May 2012 is not currently operational, but we will use it if it is repaired in time.  Participants can gain as much “scope time” as they want.

Targets selected by MHT will be dived by IMH volunteers, manually mapped, and scanned with metal detectors.  To maximize volunteer participation, those dives would be conducted on weekends and clustered geographically to meet divers.  The transit schedule would be adjusted to suit.  The project depends on IMH receiving funds to work in the Delaware River.  The Chesapeake work could then be performed along the way at minimal cost to participants.

Participation requires the usual diving waivers plus your agreement not to disturb sites, not to move or remove anything, and not to tell anyone outside the project where we went or what we found.  No take, no talk.

The tentative schedule is to depart Tall Timbers on 17 September, scan the Chesapeake sites 17-21 September, work the Revolutionary War sites 22-30 September, scan some Delaware Bay sites 1-6 October, show the IMH flag at Coast Day at Lewes on 7 October, work with the University of. Delaware for a few days to map a large shipwreck at Cape Henlopen, and dive the Chesapeake sites from (say) 10 October until Hallowe’en.


St. Mary’s River project update

Scott Tucker is investigating this site as part of his doctoral work at the University of Southampton, England.  Scott has summarized the project and posted photographs on his blog at

The site is a possible 17th century wreck that was explored before by the Maryland Historical Trust but was not surveyed in detail.  This year’s work included a Phase I reconnaissance to confirm the location and map visible features.  IMH members Dawn Cheshaek, Bob Speir, and Bob Jimenez dived.  Life member Jim Sanborn loaned us a 10-foot Zodiac that served as the primary workboat.  We also used an 11-foot aluminum skiff to carry dive and survey gear.  Water temperature was in the low 70s, the jellyfish were not too bad, and visibility was excellent for the river.

The site is heavily encrusted with dead oyster.  We laid a baseline, staked out what appeared to be the perimeter of the site, mapped features with a Total Station loaned by Historic St. Mary’s City (HSMC), and recovered three pieces of small red brick that appear to be Dutch, and three pieces of rock that might be ballast.  They seem to be consistent with the estimated age of the site.  They will be conserved by HSMC.  On the last day of the project we removed all marker buoys and mushroom anchors but left the baseline staked in situ for next year’s field season.  If funding and permits are in hand, next year’s work may include test excavations to determine if any surviving structure lies under the oysters.

another project for 2012, small to start

The Continental Navy brigantine Andrew Doria (sic) was a former merchant brig that was purchased by the Continental Congress late in 1775 and sas rerigged and converted to a warship at the Humphreys shipyard in Philadelphia.  She fought in the battles of Block Island and Nassau, received the first international salute to the American flag from the Dutch at St. Eustatius, and was burned to prevent capture near Philadelphia on 21 or 22 Nov 1777 after the Royal Navy forced the Delaware River..  Oh, those Brits….
A non-profit group called Andrew Doria – The First Salute, Inc. wants to build a replica, and wants to find and map the original to make the replica more accurate.  They think they know where the brigantine and a British prize named Racehorse were burned.
The site probably is heavily sedimented.  If the vessels were destroyed too quickly to strip them first, and if their guns were iron (probable) and are still there (doubtful), there is a good chance we can find them with a magnetometer.  However, ground-truthing any buried mag hits would require excavation, which is far beyond the scope on this initial reconnaissance.  All we could accomplish on this trip is to localize mag targets for later investigation, a necessary first step.
If First Salute is correct about where the wrecks lie, the search should only take a day or two.  I hope we can do it in April while we are in Delaware River for the Fort Elfsborg search and while we still have LAMP’s good mag on loan.  The project would be coordinated with the Naval History and Hertitage Command, and the New Jersey Bureau of Archaeology and Ethnography.  Stay tuned.  As always, contact IMH if you would like to participate.