Most of my fellow passengers had not yet arrived that crisp October morning, when I hoisted myself over the railing onto the afterdeck of the Jere Chase in Portsmouth Harbor. But a few minutes later, as the others - all docents in the University of New Hampshire marine program - boarded agilely, despite their bulky multilayered clothing, I noticed that six of them fitted the identification I had given of myself: white-haired. One most definitely did not: six-month-old Belinda, peering winsomely from her mother's zippered windbreaker, under which her carrier was firmly anchored.
Our group was made up of community volunteers who are specially trained by the University of New Hampshire (UNH) program to provide marine education to pupils in New Hampshire, Maine, and Massachusetts schools. In their school visits, docents visit classrooms to introduce displays, films, and activities that help pupils learn the ecology, industry, and lore of marine life. As part of a UNH docent-led ''day at sea'' at Paul School in Wakefield, N.H., for example, sixth-graders built a 20-foot-long whale from 92 plastic garbage bags, which they then inflated.
Docents brought live specimens of sea life to Barrington Elementary School for ''Day of the Coast''; students were asked to match them to index cards bearing a picture of a marine plant or animal and its name. Mussels, starfish, urchins, periwinkles, crabs, and seaweed were scrutinized under hand-held microscopes in this docent-provided exercise.
Sand-painting, fish-painting, and algae-pressing are other marine-related activities docents initiate.
UNH marine docents undergo an extensive orientation program, which averages eight lectures and eight field trips within a three-month period. The program is funded by the federally financed University of New Hampshire-University of Maine Sea Grant Marine Advisory Program.
I had come to sample their training and to get familiar with this innovative educational program, which taps unused, volunteer talent.
''I love it!'' said volunteer Barbara Elkerton, who lived in Puerto Rico and a number of states before settling in New Hampshire. ''I just wish I could have learned this much about each place when I was there.''
But while docents are urged to specialize, they are also required to get some ''hands on'' (or ''hands in'') experience in oceanography.
Once on board the Jere Chase, Sharon Meeker, head of the docent program, promptly ordered us to stow our gear below. She then began distributing equipment for measuring turbidity, salinity, and temperature, as our cruise proceeded from ocean to bay to river.
She held up the electronic thermometer - a wooden plank supporting a readout device, with a long probe attached. The air-temperature reading was 5 degrees C.
Two ''volunteers'' from among the 24 docents on board (21 women and 3 men) were summoned to the side rail to lower a plastic bucket into Portsmouth Harbor. They retrieved it with a splash and sloshed the contents into a tall, thin, glass beaker supported by two other volunteers. Then a hydrometer, an elongated glass bulb, was inserted into the beaker. Ms. Meeker explained that the line where the bulb touched the slightly depressed surface of the water was the measure of the water's salinity: 29 points per thousand. This was subsequently recorded as 32, after adjusting for temperature.
The turbidity factor was determined by suspending overboard a secchi disk, which resembled a garbage-can lid. The depth at which it disappeared from view - 3.3 meters (about 11 feet) - could be ascertained by counting knots in the rope which prevented its permanent disappearance.
With the first measurements concluded, the engines of the Jere Chase throbbed and we slid away from the pier. Across the water from our Jere Chase bobbed a ''gundalow,'' a local hybrid combining elements of a gondola and a Nile River scow. The flat-bottomed, flat-decked barge had its stubby mast and stout canvas folded almost to the deck to allow passage under low bridges. The vessel, Captain Edward H. Adams, is a replica of the oar-assisted, wind-, and tide-powered river barges that transported cordwood, bricks, saltmarsh hay, or livestock on the Piscataqua River system from the 17th to 19th centuries, explained Docent del Porto, a retired Boston University professor of journalism who now lives in Durham.
Kittery and the Portsmouth naval shipyard slid by, as did the Yankee Clipper, a Hafag-Lloyd line container ship. We passed great heaps of salt brought from Norway to keep New Hampshire roads drivable this winter, then under the bridges of new Route 1 and Interstate 95 and up the Piscataqua River.
Ms. Meeker explained that the current could exceed nine knots, a factor that had ''saved'' Durham from becoming an oil-refinery town. A little farther along shore she pointed out ribs of World War Liberty ships. Built here but never used, they just went to pieces onshore.
Ms. Meeker also pointed out Kevin Tracy's Belon oyster project. With seed oysters from Europe, Japanese-lantern trays, and intensive sea-farming techniques (which include pulling the oysters from their watery beds to give them daily baths to prevent exterior accretions), Mr. Tracy now raises oysters and sells them back to Europe and to New York restaurants for 35 to 40 cents each.
A lively debate then broke out as to whether a bird in the distance was a black duck or a cormorant. The decision was deferred to Ruth Morris, a docent whose special area of interest is ornithology. She announced it was a cormorant, then borrowed field glasses to confirm her opinion.
The Jere Chase drew up to a dock at Jackson Lab, a marine station at Adams Point manned by people from the University of New Hampshire. Here two of the three oceanographic measurements were repeated with results that surprised no one: Farther from the ocean, the water had less salt, and the temperature was warmer. But the turbidity was surprisingly higher, because of a stronger current through Furber Strait, which separates Great Bay from Little Bay.
As we moved into the Lamprey River, green and gladed, we passed weirs where alewives come up in the spring. Joe del Petro, a docent whose specialty is marine history, explained that evidence of this ancient fishing technique was found in Boston, when foundations were laid for the John Hancock Building. ''Indians used the weirs,'' he said.
At Newmarket, the Jere Chase made its third and final landing. Nearby is a marine station, part of a four-year effort by the New Hampshire Fish and Game Department to develop coho salmon ranching in the Lamprey. The docents peered through a grill into the ladder (a vertical succession of small pools) the salmon use each fall to reach their spawning grounds. Bob Fawcett, an aquaculturist, netted seven of the shimmering creatures (8 to 12 pounds each) for the docents to see.
''How will all the information dispensed today be translated into the school programs the docents give?'' I asked Ms. Meeker, as we reversed direction and headed back to Portsmouth.
''Maybe in enthusiasm and appreciation,'' she replied, reminding me that this day's field trip was just one-sixteenth of the total orientation program.
That reminded her to remind the docents to report for their next session, a lecture, the following day.