A long winter of frequent storms, from October’s Hurricane Sandy to a three-day storm in early March, has been especially difficult for a group of frequent Island visitors: the Steamship Authority’s fleet of vessels, the hardy group that connects the Vineyard to the mainland.

Rough seas have contributed to 94 ferry cancellations in the first two months of 2013 alone, five per cent of the 1,892 scheduled trips, according to data provided by the Steamship Authority. This is almost four times the number of cancellations compared to the same period last year, when there were 26 cancellations out of 1,924 trips during a much milder season.

The M/V Island Home, the newest and largest of the ferry fleet, was cancelled most often so far this year out of passenger ferries: 47 of Island Home’s trips were cancelled in January and February, almost six per cent of 794 scheduled trips. The M/V Martha’s Vineyard, on the other hand, was cancelled about four per cent of the time. The freight boat M/V Sankaty was cancelled more often at 6.6 per cent of 336 trips.

Data provided by the Steamship Authority did not specify how many of the trips this year were cancelled strictly due to weather. But most Islanders have noticed that the same storms that have caused severe erosion and led to prime sledding conditions have halted ferry trips; the winter storm the weekend of Feb. 8 suspended ferry service from 2:30 p.m. on Friday to 6 a.m. Sunday.

“This year in particular seems to be more storms, longer in duration,” Steamship Authority general manager Wayne Lamson said.

Anecdotally, Mr. Lamson said a three-day storm on March 6, 7 and 8 might have led to the most ferry cancellations for this winter season.

After long periods with no service, he said, priority is given to trucks carrying fuel and food when service resumes.

Decisions to cancel ferry trips are up to each individual captain, Mr. Lamson said. When captains arrive for work, they have access to weather reports, tide information, vessel reports and information from a weather buoy in Nantucket Sound and a weather tower in Buzzard’s Bay.

“All these tools are at their disposal,” Mr. Lamson said, and they talk to port captains and get reports from other vessels on sea conditions, he added.

The features of each vessel can also impact decisions about when passage and docking are not safe. For example, the Martha’s Vineyard, which has entry and exiting on one side of the boat, might be able to make it in one direction and not the other, Mr. Lamson said, because conditions might not be safe for the boat to back up and turn around. The double-ended Island Home doesn’t have this problem.

But the Island Home, which took her maiden voyage in Vineyard waters in March 2007, has her own concerns. The ferry is 255 feet long and cost $32 million, and was built to carry large amounts of people; it can carry up to 1,200 passengers and up to 76 vehicles.

The ferry is slightly taller than the others and has a larger outboard profile, Mr. Lamson said. When the wind picks up, its larger size “makes it a lot harder to dock the vessel, to make the trip, whereas the Nantucket has a lower profile compared to the Island Home,” he said. Mr. Lamson said the Steamship Authority gets comments that the Island Home isn’t as reliable as the Islander, the vessel it replaced in 2007. But its larger size “gives us a little more capacity,” he said. “We’re trying to keep up with the demand.”

Looking at year-round data, it appears that the Island Home’s cancellation rate is higher than the other main passenger ferry, the M/V Martha’s Vineyard.

In all of 2012 the Island Home was cancelled because of weather 62 times out of 4,518 scheduled trips, or roughly 1.4 per cent of all trips. The Martha’s Vineyard, which also docks in Oak Bluffs, was cancelled about .2 per cent of the time because of weather, missing only eight of 3,767 trips.

The M/V Nantucket and the freight boat M/V Katama had higher weather cancellation rates. The Katama was cancelled about 2.2 per cent of the time because of the weather, and the Nantucket was cancelled about 2.7 per cent of the time. On the other hand, the freight boat the M/V Governor had a weather cancellation rate of .2 per cent, and the freight boat M/V Sankaty made all 1,582 of its scheduled trips.

The Island Home does seem to be cancelled slightly more in the off-season months with rougher weather. From October through December of 2012, the Island Home had 42 trips cancelled because of weather, for a cancellation rate of 3.9 per cent. The Nantucket had trips cancelled because of weather about 3.8 per cent of the time, while the Katama had 3.4 per cent of trips cancelled because of weather during those months.

The Martha’s Vineyard, which was dry-docked for part of the fall for regularly-required maintenance, made all of its 201 trips as scheduled.  The Island Home is currently dry docked at the GMD Shipyard Corp. in Brooklyn, N.Y. for scheduled maintenance, including a required US Coast Guard hull exam, underwater hull cleaning and painting, installation of sewage holding tanks and evacuation piping, and machinery inspection and repairs.

In all of 2012, ferry trips between Martha’s Vineyard and Woods Hole were cancelled 150 times out of 14,930 because of weather.

Mr. Lamson stressed that the Vineyard has it easy compared to its sister island, Nantucket. The trip between Woods Hole and Martha’s Vineyard is relatively sheltered, Mr. Lamson said, compared to the voyage between Hyannis and Nantucket. The other island can see service suspended for three or four days at a time. “It’s a little bit more susceptible to high winds and high seas,” Mr. Lamson said.