Donald Leach; gleaned insights from Washington diaries; at 80

Donald Benjamin Leach graduated from Massachusetts Maritime Academy and also taught the Kennedy brothers - John, Robert, and Ted - how to sail. (Leach Family via Washington Post)

WASHINGTON - Scholars at the Mount Vernon research library who glanced up from their 18th-century gleanings a few years back might or might not have noticed an older man in a blue security guard's uniform sitting at a table among them. They probably did not know that he used his lunch hour every day to trudge up the hill from his guard post at the wharf and pore over George Washington's diaries.

Or that he was a retired Navy commander who ended his military career as the intelligence officer in the office of the chief of naval operations.

Or that the results of his original research offered new insights into Washington as a commercial fisherman and Mount Vernon as an ambitious commercial fishing venture.

Donald Benjamin Leach, who died March 5 at age 80 of an aneurysm in Alexandria, Va., was a Navy man who spent 25 years on the water or on-shore assignments. "He loved the Navy," his wife, Vivian, said in a recent interview at Mount Vernon.

A New Englander, he graduated from Massachusetts Maritime Academy, taught naval science at Maine Maritime Academy, and served on an aircraft carrier, an icebreaker, a fleet tug, a destroyer, and as executive officer on a cable-laying ship that kept track of Soviet submarines during the Cold War.

He also taught the Kennedy brothers - John, Robert, and Ted - how to sail.

"There was something about Don that let you know that ocean water ran in his veins," said Sue Keeler, a longtime guide at Mount Vernon and now coordinator of VIP visitors.

After he retired from the Navy in 1974, Mr. Leach worked for 14 years on the Navy's undersea surveillance program for the defense company TRW. Retiring a second time in 1988, he knew he had too much energy and too much passion for learning to sit around the house. Spending time with his fellow ROMEOs, Retired Old Men Eating Out, wasn't enough, so he took a part-time security job at nearby Mount Vernon.

As wharf master for the historic estate, 16 miles south of Washington, he tended to the tourist vessels that docked twice daily and pondered the broad Potomac. Having been around water all his life, he knew intuitively that the river must have been busier and more vital than historians realized.

He studied Washington's diaries with a sailor's eye and soon realized that he was reading the entries of a fellow waterman. In the course of his research, he learned that the young Washington considered entering the British Royal Navy - his mother refused permission - and, on a voyage to Barbados with his half brother Lawrence, took a keen interest in navigation, weather, and shipboard routine.

When Lawrence died, Washington ran Mount Vernon on a lease from his widow. He inherited the estate when she died in 1761.

The deeper Mr. Leach went into the diaries, accounts, and ledgers, the more he realized that harvesting fish from the bountiful Potomac was an integral part of the revenue-producing activities of the large working plantation.

Mr. Leach came to appreciate the technical and logistical challenges that Washington and his waterfront neighbors confronted with their nascent fishing industry: what size seining nets to use; how to harvest huge runs of fish in a short period of time; how to mobilize a labor force large enough to clean, preserve, and pack the fish; where to get sufficient barrels; where to buy salt to preserve the fish; how to dispose of the slimy byproducts.

Relying on the labor of slaves Mount Vernon in 1772 alone harvested 1.3 million herring and 10,894 shad. Packed head to tail in barrels - about 800 to a barrel, with alternating layers of fish and salt - the fish were shipped to Jamaica and New England and occasionally to Europe.

"Don ended up being our expert on the river," said James Rees, Mount Vernon's executive director.

Mr. Leach's research informed the fishing diorama in the new museum and education center, and the information he uncovered is included in the staff manual for Mount Vernon's employees.

Mr. Leach was accustomed to commanding ships and people - as Rees noted, "he didn't suffer fools gladly" - so it wasn't easy for him to have to gently and persistently persuade the experts over a period of years that what "the security guard" had discovered was noteworthy.