The chief scientist was seasick, along with most everybody else on the Warfield, an unlikely-looking ship in an unusually severe storm near the mouth of Chesapeade Bay.

But despite the wind and heavy rain, the crew lowered the cylindrical meter that would measure the water's saltiness into the murky depths. Inside the floating laboratory, scientists recorded the results and tried desperately to keep their balance -- and their lunch.

Nobody ever said solving the mysteries of Chesapeake Bay would be easy.

The Chesapeake, in fact, is among the most studied and least understood bodies of water in the world. Almost every researcher has a theory about the biological state of the nation's largest estuary, but the truth is there is no simple scientific answer to the critical question, "Is the bay dying?"

The human impact on the bay often has been subtle, measured by the memories of a struggling port town such as Havre De Grace or the embattled stance of the Talbot County gentry fighting off development. The physical change is there to see for anyone who finds a beach polluted or a species of fish more scarce.

Yet in the end, poet and scientist face the same problem in trying to capture the present and predict the future of an organism as complex as Chesapeake Bay. That something major is happening here is beyond doubt, but from that point on, genralization gets dangerous.

"I've been trying for years to get the message across to administrators and legislators," said Jay Taft of the Johns Hopkins University's Chesapeake Bay Institute, which owns the Warfield. "You can't look at one fish kill and say the bay is polluted or at one productive area and say the bay is healthy."

While the public clamors for quick answers and visible vilains, scientists such as Taft tend to take the longer view. "One of the biggest problems we have, frankly, is getting the public to understand that a measurement in a particular place comes from all these things -- sewage, river, ocean and material from sediments. There is a mix. Our job is to sort them out."

So it was that Taft and more than 100 other scientists embarked last week from Annapolis on a journey that he and the others hope will be different from the dozens of other studies of Chesapeake Bay.

For those aboard the 106-foot-long Warfield and six smaller vessles stationed around the bay, it was a kind of mission impossible. Agencies and institutions which in the past produced pieces of the Chesapeake puzzle that have never quite fit together were working for once in unison, at a single time and for a single purpose.

The voyage of the research vessels is part of the federal Environmental Protection Agency's Chesapeake Bay research project, a five-year, $25 million study. Up and down the bay for an intense eight-day period, the ships have been gathering standardized data that will be fed into a computer and ultimately, it is hoped, reveal how much punishment the bay can take.

This part of the project will cost an estimated $1 million and is the most ambitious single study of the bay ever undertaken. But as with all such studies, the painstaking work of measuring and recording, of collecting and analyzing, will not produce instant results. "So many people think when you go out, the next day when you come back you'll have the answers," said research associate Laurie Brice. "It just doesn't work that way."

"It's not a National Geographic special or a Jacques Cousteau movie," said Taft, a serious-looking man who seems younger than his 36 years. "It becomes dull and routine."

Carrying six scientists, six crew members and a Washington Post reporter and photographer, the Warfield departed in an early-morning drizzle last week from its berth in Annapolis. Its destination, 120 miles and 10 hours away, was the mouth of the Chesapeake and then a stop for the night at Norfolk.

On the way, the Warfield would stop nine times to measure temperature and electrical conductivity at different depths, information from which the water's saltiness is determined.

The storm that plagued the trip was not the normal summer kind that regularly wells up in late afternoon on the bay, violent but short, raking the skies with lightning, thunder and heavy rains. Rather, it was a sustained squall with 30-mile-an-hour winds that stirred and slapped six-foot white caps against the bows of the Warfield, a twin-hulled catamaran.

In the crew's lounge, which straddles the ship's two hulls, the deck rose and fell as the water went whop, whop underneath. John Klein, an EPA Chesapeake specialist struggled to stand and peer out of a forward porthole.

"I wanted to make sure the front of the boat was still there," he said weakly.

Tom Pfeiffer, the EPA coordinator on board, recalled an earlier trip carrying foreign scientists that ended prematurely when the head of the Chinese delegation got sick. This time, though, there was no turning back.

Everyone involved in the project believes the stakes are high. "There are a lot of political pressures from citizens, states and agencies trying to sort out what has to be done about the bay and how," David A. Flemer, senior science adviser to the Chesapeake Bay research project, had said a few days earlier in his Annapolis office. "If we as scientists can better inform, there will be a high payoff for decision-makers in the future."

The Warfield expedition would be a small but important part of that effort.

Starting the next day, in calmer waters, the Warfield would cross and recross the mouth of the bay, following a carefully prescribed route and routine.

At each of three "stations" along the way, the scientists would check first for salinity, then, dropping a lightmeter into the water, for cloudiness, and finally, pumping aboard water samples, for analysis of nutrients.

It is the nutrients -- chemicals such as nitrogen and phosphorus -- that, more than a specific sewage plant or any one industrial polluter, suck the life-sustaining oxygen from the waters of the Chesapeake Bay.

Washed by rain from farms, shopping centers and subdivisions into the 150 rivers and tributaries that feed the Chesapeake, the nutrients settle in the sediment on the bottom of the bay. They then seep into the water but no one knows how much and to what effect.

"We first looked at what was coming out of, say, the [District's] Blue Plains sewage treatment plant," said the EPA's Pfeiffer. "Now we find sediment in the middle of the bay to be more important."

"It is one of the real gaps in our knowledge," said Taft.

Another gap is the rate at which the bay flushes the pollution from its system, as water travels back and forth between the Chesapeake and the ocean. An effort to close that gap as well is being made this summer in conjunction with the nutrients study. Some of the same scientists deployed 60 current-measuring devices from the Chester River in the upper bay to the area just outside the Chesapeake Bay Bridge Tunnel where the estuary meets the Atlantic.

During the meter deployment, they wore "CRIMP" T-shirts, for Chesapeake Research Information Model Program. And on the way down to measure nutrients last week, the researchers joked about "crimping" and someone suggested serving "crimp cakes" and passing out "crimp statues" at a "crimp award" ceremony next month.

The first day out of Annapolis, the jokes came in handy. The rain let up in the afternoon, but not the wind as the Warfield plowed through the wide lower bay. Few other boats and no land appeared on the horizon. All there was, it seemed, was open sea.

The "stations" were already marked by buoys at the mouth of the bay. Nearby were the meters for measuring current, or so the scientists hoped. "If the fishermen had a bad day," said Taft "they'll go to one of our buoys, drag around it and turn in a meter for a $250 reward. They cost $7,500 each and we're willing to pay to get them back. For a while, there was one particular fisherman who was recovering current meters for us with great frequency and being rewarded each time."

There was no proof the buoys had been stolen, of course. "We can't separate fact from fiction," Taft conceded. "We can only conjecture."

By the time the Warfield arrived at the Little Creek Naval Amphibious Base outside Norfolk it was after 7 p.m.

Meeting the vessel, was a Chesapeake Bay Institute official, carrying among other things, a new buoy to replace the lighted marker that had somehow sheared a rod and washed ashore in front of a restaurant. "The owner said business is great, everyone is coming to the flashing light," Taft joked.

The next day's weather was clear, the water was calm, and the Warfield's crew easily fell into their routine of scientific research. By 11 a.m., the vessel had stopped at two of its three assigned stations and Klein was happy. "Well at least all our buoys are there so far," he said.

Under Klein's direction, crewman Chuck Wessels brought the ship's submersible water pump up to seven meters. "Randy, got your D.O.?" Klein then asked staff biologist Randy Loftus, who was testing for "D.O." -- dissolved oxygen -- with a device called a microwinkler. Loftus nodded, and the pump was raised to three meters below the surface.

"When you take two samples from a bottle, that's chemistry. When you take from the ocean, that's oceanography," explained Taft. Everyone laughed.

There were moments, too, of drama along the way. At one point, a large freighter loomed to starboard of the Warfield after the research ship had drifted into the shipping lane. Quickly, the engine was put into reverse, and the crew resumed their work.

Another problem was the filter pores. Microorganisms smaller than expected were sneaking through the paper filters, clouding up the samples and clogging the filter frits (a glass sponge underneath) in the process. There were filters with smaller pores, but not enough of them.

"We'll have to make a correction when we do the analyses," said Taft.

Climbing up to the bridge, Taft contacted another research vessel over the marine radio to discuss the problem. The other vessel, the University of Maryland's Aquarius, wasn't encountering the same problem at its two stations thereby.

As the day wore on Charlotte, the cook, sunbathed on the front deck while on the radio a Norfolk station played "Won't you let me take you on a sea cruise." An afternoon haze made the big freighters anchored around the Warfield appear to be floating in the sky.

By sunset, the Warfield had visited each station roughly four times, and as the march of science progressed the stations began to blur together for some of the crew.

Which station were we at, Randy Loftus was asked. "I'm not really sure anymore," he said. It didn't matter, though. Someone else had written it down.