A conch fisherman working off the coast of West Chop got caught in a pot line last summer and was pulled underwater off the stern. He was hauled back in and revived by a quick-witted captain, and thanks to the Coast Guard, was rushed to the hospital where he was stabilized.

Just weeks before and a few miles away, Coast Guardsmen followed a 94-foot scalloper into the port of New Bedford, conducted a boarding and discovered an illegal catch in its hold.

Dramatic rescues and vessel inspections are all part of the job for the 22 men and women of station Menemsha, who keep a watchful eye on the Vineyard and its surrounding waters. Whether skies are blue or winter gray, the Coast Guard remains on continuous alert.

During its last fiscal year which ended Sept. 30, Coast Guard personnel from Menemsha responded to more than 42 cases and made over 180 boardings. Menemsha is augmented by the Woods Hole station which monitors the waters off Vineyard Haven, Oak Bluffs and Edgartown. Last year the Woods Hole station handled 90 cases in their area of jurisdiction. Most of the Coast Guardsmen are in their 20s.

Coverage over the water extends aloft. The Vineyard, Nantucket and much of southeastern New England is under the supervision of the Coast Guard Cape Cod Air Station. Last year that station handled over 300 cases involving mostly search and rescue. Acting as an air ambulance, four times the Coast Guard deployed either its Falcon jet (twice) or MH-60T Jayhawk helicopter (twice) to the Vineyard to evacuate a Martha’s Vineyard Hospital patient to the mainland, because weather was so troublesome the usual commercial air ambulance couldn’t fly.

For the third summer, the stations also provided backup and support to those agencies involved in making sure the President of the United States and his family had a pleasant summer vacation in Chilmark.

To senior chief Jason L. Olsen, 36, a huge part of the station’s mission, no different from the rest of the Coast Guard, is readiness, and a substantial amount of resources are committed to training and service and being on the water throughout the year.

“We practice at least a couple hours a day,” Mr. Olsen said. “People forget. We aren’t just getting under way. We are out practicing. We also maintain these vessels.”

Of the 180 boardings, the senior chief said 90 per cent were random. Boardings were done on both commercial fishing boats and recreational boats, in most cases in the interest of safety. Some 18 boardings involved intelligence gathering. The senior chief would not discuss the cases other than to say they may have involved law enforcement or immigration fact-finding.

Station Menemsha covers the waters west of Westport to all of New Bedford, east to Tarpaulin Cove, and all of the Vineyard’s north shore. To the south, the station covers the waters 50 miles offshore.

Mr. Olsen said the greatest challenge in the area is tied to the environment, where the weather and the seas can be unkind. The Guard has heavy-weather coxswains who are qualified to go out in 40-knot winds and 20-foot seas.

“The boat, the 47-foot motor lifeboat, is rated to go into more seas, we just don’t have that qualification,” the senior chief said. The aluminum vessel can withstand flipping over and righting itself in from eight to 12 seconds, he said.

Early in the summer, the Coast Guard station personnel used that lifeboat to follow a 94-foot sea scalloper into New Bedford harbor. Once the vessel was tied up, the Coast Guard did a safety inspection and a space accountability check. In the process, Mr. Olsen said, they discovered a hidden compartment onboard where the fishermen could store an extra amount of harvested sea scallops, which is illegal.

In the first week of August, the station rescued three fishermen who escaped from a boat that sank south of the Vineyard. They were first picked up by a 101-foot commercial sea scalloper called Patience, but the Coast Guard transported the soaked boaters to Menemsha where they were evaluated and released.

In early August, three crew members from the station volunteered to help Chilmark harbor master Dennis Jason move a 38-foot Sea Ray cabin cruiser out of the harbor. The boat, tied up at the slip at the transient dock, was discovered filled with the noxious odor of volatile gasoline. With the owner away, Mr. Jason towed the boat out beyond the jetty to a mooring to protect the boats in the surrounding inner harbor. “We had a dangerous situation. We were concerned the boat was going to explode,” Mr. Jason said.

Days after Hurricane Irene passed far to the east of Nantucket, there was an incident in the Menemsha channel. Mr. Jason said a power boat transiting the channel hit a new sandbar that had arisen as a result of the storm. When the boat ran into the bar, he said: “The people in the boat lurched forward.” One of the passengers suffered a serious head injury. “We had some of the Coast Guard come along and give us a hand. They helped us transport the injured to the dock,” he said.

“Any town that has the Coast Guard, they would all have to agree that they are a good response team,” Mr. Jason continued. “Menemsha is a strategic place to have a Coast Guard station. There is a fishing fleet that fishes off Gay Head and offshore all the year round. In the summer we get all the yachting visitors. People are transiting Long Island Sound up to Vineyard Sound.”

Station Woods Hole covers the waters from West Chop east to Cape Pogue to Hyannis and three quarters of Muskeget Channel.

That station’s senior chief, Brian Guarino, said the rescue of the conch fisherman was one example of how the Coast Guard serves the community. “It is a hazardous way to make a living. There are a lot of risks.” The Coast Guard did one boarding off Falmouth and found marijuana aboard. The case was turned over to the Falmouth police.

But the bulk of the Coast Guard’s work involves safety. Senior Chief Olsen said the one message he would like to give to boaters is that they should always let their loved ones or a friend know where they are going before they leave the dock. It is a called a “float plan.”

Another piece of advice? “Use the marine radio,” the senior chief said.

“Never hesitate to call us on channel 16, or call by cell phone 911. It is better to call and not need us, than to need us but not call.”