It was impromptu; sometimes hard to catch over the noise of the wind and waves, and the growl of the waterman's engine.
But it was among the finest- ever discourses on the Chesapeake blue crab -- the crustacean equal of dropping into the Athenian marketplace as Socrates and Plato dialogued.
At center stage on this autumn day a few years ago was Edward Harrison, a Smith Islander who, during his 70-odd years on the water, caught more soft crabs than anyone who ever lived.
Ed's old wooden boat was surrounded by rafts carrying Stanford University alums from a cruise ship -- CEOs, academics, physicians -- raptly attentive to their fourth-grade-educated lecturer.
Orchestrating it was the cruise's nature guide, Dr. L. Eugene Cronin, Ed's longtime friend and student; also an eminent crab biologist who began his scientific career when most Chesapeake watermen were just figuring out how to use a crab pot (an invention patented in 1938).
Still teaching today about his beloved Chesapeake to anyone who will listen, Gene Cronin, now 78, has spanned in his career an unsurpassed range of bay science, history, politics and education.
This June, he got the prestigious Mathias Medal for bay science, the second time it has been given since being established a few years ago in honor of retired Sen. Charles McC. Mathias.
The senator, whom Cronin advised on the bay beginning when he was a state legislator, was moved by the estuary's growing problems to make a personal field tour nearly 20 years ago. From this, Mathias became the prime mover in starting the current Chesapeake Bay restoration program.
Cronin came by his calling naturally enough. A cousin of the late decoy carver Madison Mitchell, he was born and raised in Aberdeen, near the famous waterfowling reaches of the Susquehanna Flats.
He was teaching high school biology in Bel Air in 1941, when he answered a brochure advertising summer courses at the old Chesapeake Biological Laboratory at Solomons.
In short order, Cronin fell in love with zoology, was offered an appointment at the lab, and did his master's and doctorate on the biology of the blue crab.
He was assigned by Dr. Reginald V. Truitt, founder of the laboratory, "to master crabs," Cronin recalls.
The crab had been studied by scientists such as W. K. Brooks of Johns Hopkins as early as the 1890s, although that highly regarded researcher inexplicably made a major wrong conclusion:
"He wrote twice that the mature female crab sheds her shell again after spawning, and they never do," Cronin says.
No researcher at the time had much understanding of how crabs interacted with the Chesapeake system; why they fluctuated so from year to year between scarcity and abundance.
Dr. Truitt, Cronin says, "gave me some very smart advice on setting out -- 'get out and spend time with the very best watermen in every community around the bay.'
"I did, and what an education. I think every scientist should still do something like that."
From people like Ed Harrison and his equivalents in Rock Hall, Toddville, Crisfield and half a dozen other communities, Cronin during the next several years would accumulate a wealth of crab statistics -- and an equally great trove of stories, which he is just now beginning to write down.
He was always fascinated by the marvelous efficiency of the crabs' reproduction. Females become able to reproduce only on their last shed, or molt (a crab grows by shedding more than 20 times in its two- to three-year life).
The female at this juncture is a soft crab for the last time; and because she can be impregnated only when soft, she has just this one chance at joining with a male -- and she gives it her best.
Cronin recalls a waterman showing him a female, just shed, "rolling over on her back, fanning her abdomen [site of the genitalia] to attract males.
"He said, 'Boy, ain't that the hottest thing you've ever seen?' -- and he was right."
Such behavior, aided by secretion of a pheromone, a sex-attractant odor, is so effective that Cronin says he has examined thousands of adult females during several decades, and can only recall "two, maybe three, that were not impregnated."
"The pheromones work, and they work with an efficiency that is )) almost unbelievable."
Cronin would go on to be director of Maryland's bay research labs during three decades, forming, along with Donald Pritchard at Johns Hopkins and William Hargis at the Virginia Institute of Marine Science, what was known as the "big three" of bay science.
Those were simpler days. The three were at a conference in late June of 1972, when it began raining -- heavier than anyone had ever seen it -- all across the bay region.
With little more than a brief consultation, the directors launched an unprecedented, bay-wide sampling effort.
They would document, in a substantial book, the chemical, physical and biological impacts of Tropical Storm Agnes, whose floods proved one of the more significant natural impacts in the bay's recorded history.
I asked Cronin whether, in retrospect, the "big three" might better have prevented the broad decline into which the bay slipped during the 1970s and early 1980s.
He said some areas that are now recognized as major problems of the bay -- agriculture and airborne pollutants -- "we just didn't connect at the time, and that's a little embarrassing."
"But most of the warning signals, we raised in a paper as early as 1964 . . . and in bay conferences in 1968 and 1977. Pritchard in the mid-60s said nutrients [the biggest bay problem now] were going to be the big problem.
"But we didn't have the political support, and we often didn't have the quantitative data to prove our case."
Looking back, one also realizes how rapidly some threats went from mild to major in only a few years -- farming's use of fertilizers, and commercial and sport fishing pressure, for example.
As for the blue crab, Cronin remains concerned that for all our increased knowledge of it, "We still manage it as two different states and several different fisheries, when it is a single, bay-wide species."
He is not shocked that scientists' predictions last winter of a good harvest now seem over-optimistic.
"Everything about the crab is complicated," he says. "Every time someone has developed some neat hypothesis, the crabs eventually do something different."
He says science may now be moving close "to glimpsing" connections that might provide a basis for real crab prediction.
But he thinks we might also remain as frustrated as a Virginia congressman, who conducted hearings on the great -- and still mysterious -- crab shortage of 1968:
"After he heard all the conflicting theories, he said it reminded him of the man who went to his doctor with a mysterious ailment."
" 'You've had this before haven't you?' the doctor said.
" 'Yes, I have,' answered the patient.
" 'Well, you've got it again.' "