revised plan, autumn 2015

It was disappointing to cancel our big fall projects up the Potomac, but we can focus on the Lord Dunmore project instead.  It would be very valuable to Maryland and IMH to find and prove a vessel that was scuttled by Dunmore in the summer of 1776.  That would be the first underwater site dating from the Revolution found in Maryland.  Historical records say between eight and 23 vessels were burned, so we are looking for stone ballast piles and associated debris.

The site is convenient to Tall Timbers and does not present the logistical constraints the Potomac projects posed.  It can be done in stages on weekends, and it offers good ancillary training in boat handling, sidescan operation, and magnetometer operation once we get that puppy to work.

Depths are 10 to 20 feet.  The bottom is hard, and visibility is unusually good by Potomac standards.

Prior scans by Azulmar, LAMP, and IMH with sonar and magnetometer covered about half the target area and disclosed several dozen protruding objects that need to be mapped and assessed, and at least 23 isolated magnetic anomalies that need to be refined, found, and assessed — plus two linear magnetic targets hundreds of yards long.  Those probably are underwater cables, perhaps left from the US Navy torpedo test station that operated in the area from 1941 to 1959, or electrical cables that once powered a lighted aid to navigation.  That speculation needs to be proved or disproved.

So, the revised plan for autumn is to dive and map the Dunmore site every weekend the weather allows, starting this Sunday, 20 September.  (Saturday 19 is out.)  Most weekdays are available too, if we have divers.  The standard plan will be to meet at Tall Timbers at 0830, load up, get underway by 0900, arrive on site and start diving by 1015, secure at 1600, and dock at Tall Timbers at 1715.  Two tanks should be enough.  Roper will carry spare tanks with yoke fittings.  We will anchor or live-boat, depending on location, conditions, and manning.  Mapping will be done by sonar, offsets, and trilateration.  Bring a tape, slate, and lunch, and confirm with me by email or phone (302-222-4721) the day before you come.