REDMOND, Wash. - Over lunch at his home near Seattle, former Chesapeake scientist Donald Heinle recalls one of the clearest views anyone ever had of the bay.
It was windless, late fall or early winter 1963, and Heinle was an observer aboard a military transport that had just scrubbed its mission of dropping paratroopers at Virginia's Fort A. P. Hill. The pilot wanted some flight hours under his belt anyhow, so he flew up and down the length of the Chesapeake. He opened the plane's huge rear cargo door, and for four hours Heinle, a doctoral candidate at the University of Maryland, had an unparalleled view of the 2,500-square-mile estuary passing beneath him.
He was not just seeing the bay that day. He was seeing the bottom of the bay - nearly all of it, everywhere but the narrow ship channel, ancient gorge of the Susquehanna River.
Looking at depth charts later, Heinle says, "I must have been seeing 30, 40 feet deep. It made a strong impression on me, because I grew up around Puget Sound, which is hundreds of feet deep. To be able to see the bottom in such a huge body of water was just amazing."
Granted, Heinle's peek came in colder weather and in a low-rainfall year, when the water would be at its clearest. Even so, the notion that anyone in modern times could see most of the Chesapeake's bottom is amazing to anyone familiar with the bay, where nowadays it is hard to see your feet while standing waist-deep.
Runoff from human activities has clouded the water to the point that vast meadows of underwater grasses that dominated the bay's bottom for hundreds of thousands of acres have declined by 90 percent or more.
They just don't get enough light anymore. Bringing those grasses back - there are 16 varieties - is considered critical to restoring the Chesapeake ecosystem. They are prime habitat for everything from seahorses and scallops to molting soft crabs and the young of fish - also food for waterfowl.
The grasses also absorb and settle out the pollutants clouding the bay, and their thick growth in the shallows dampens the erosive energy of waves before they hit the shorelines.
I had a graphic demonstration of this erosion-proofing. Paddling my kayak at night, I was confused by the water's turning abruptly and randomly from smooth to a fierce chop, and back, several times. The next day I saw I had been traversing alternating patches of thick grass and bare bottom.
How clear were the bay's waters when the grasses grew lushly? It's a vital question now that we are spending billions on restoring the estuary. But no one began to measure clarity systematically until after the problems had set in.
There are tantalizing anecdotal accounts, however, in addition to Heinle's. Frank Leslie's Illustrated Newspaper, in the Feb. 10, 1866, issue, talks of canvasback ducks feeding on wild celery that grew on shoals "eight or nine feet deep" in the upper bay, where the water now is some of the bay's most turbid.
I have had old Smith Island soft crabbers show me places they used to work in thick grass, where the water is 15 to 16 feet deep. Bernie Fowler, a former state senator from the Patuxent River area in Southern Maryland, holds an annual "wade-in" to commemorate when he could walk out as a young man, shoulder-deep, and see his feet. He says crab nets then used handles as long as 10 to 12 feet to dip crabs on the grassy bottoms.
Average underwater visibility there now is less than two feet. The late Dixie Buck, who made a living dipping soft crabs off the Patuxent's bottom, told me once that she could detect slight changes in clarity beginning in the mid-1950s, and certainly by the mid-1960s.
Heinle, who was doing water-quality research on the Patuxent by the mid-1960s, was picking up those same changes with his scientific instruments.
As it turned out, the young scientist who saw the bay so clearly from a plane in 1963 ended up putting his neck on the line to bring back a clearer, grassier Chesapeake. By the late 1970s, Heinle, then a top University of Maryland bay researcher, was opposing plans by Maryland and the federal Environmental Protection Agency to clean up the Patuxent.
His studies indicated that the plans were ignoring a key pollutant. More than once, state natural resources officials tried to get him fired for his concern. In the end, a federal judge ruled against the government.
Heinle's courage resulted in the historic, baywide commitment to reduce nitrogen from sewage and fertilizer runoff.
Those must have been trying times, I remarked during my visit. He responded by telling me about the time, surveying salmon streams as a college student, when he faced down a charging brown bear, armed only with a willowy, 12-foot salmon spear.
"Ever since, if something is pushing on me and the consequence is less than death, I haven't worried much about it," he said.