BAR HARBOR — When College of the Atlantic took delivery of its new research vessel Osprey last December, skipper Toby Stephenson was excited about the boat’s ability to work offshore and ferry students to the school’s installations on Mount Desert Rock and Great Duck Island.

Last week, though, Osprey’s baptism as a teaching tool took place much closer to home — tucked in the lee of Burnt Porcupine Island in sight of the COA campus.

Still awaiting the Coast Guard certificate that will allow the boat to carry as many as 36 passengers in addition to a crew of two, Stephenson and Osprey took five members of Professor Sean Todd’s Introduction to Oceanography course on a short cruise Friday afternoon, where they got their first taste of what scientists who study the sea really do.

With Todd kept shorebound fighting off some kind of bug, teaching assistants Ashley Heinz, a graduate student pursuing a Masters of Philosophy in Human Ecology, and undergraduate Katie Mathews introduced the class to the techniques of towing a plankton net and using a CTD (continuity, temperature, depth) meter to measure water temperature and salinity at various depths. Electrical continuity can be measured to determine the salinity of seawater.

Shortly after lunch, student deckhand Alex Borowicz cast off the lines and Stephenson conned Osprey toward the first of six “stations” at which the students would take turns deploying the CTD sensor and reporting their findings to Heinz for recording. Although the weather was mild on shore, a stiff breeze blowing up Frenchman Bay made jackets a necessity on deck and the still chilly water made for cold, red hands for anyone handling the wet plankton net and CTD gear.

For more maritime news, pick up a copy of The Ellsworth American.