In the first four months of 2018, the Steamship Authority had 549 ferries cancelled because of mechanical problems, more than triple the number of ferry breakdowns in the four previous years combined.

In total, the boat line saw 870 ferry trips cancelled on the Vineyard route between January and April because of mechanical breakdowns, weather issues and end-of-day freight trips that were not needed.

By comparison, in all of 2017 there were 484 cancellations, 26 due to mechanical breakdowns. A total of 148 ferries were cancelled for mechanical reasons from 2014 through 2017.

The numbers tracking cancellations from 2014 through this year appear in a staff summary circulated among boat line board members Monday prior to the monthly Steamship Authority meeting on Nantucket next week.

“I think the numbers speak for themselves,” Vineyard SSA governor Marc Hanover said. “It’s clear we have a huge problem and it needs to be corrected.”

The 14-page report highlights the growing crisis around the boat line over the problems on the Vineyard route and outlines a plan to improve SSA operations, as an alternative to a costly proposal submitted by McKinsey and Company last month.

The McKinsey proposal and its $500,000 price tag is also detailed for the first time in the staff report.

Mr. Hanover has called for the outside independent review, but at a meeting on the Vineyard in April his fellow board members took a different tack, instead asking management to present an alternative plan within two weeks.

Growing controversy now surrounds the SSA over an unprecedented spate of breakdowns and disruptions in service that began in mid-March on the Vineyard route. In April the problems appeared to be solved, but last weekend the ferry Martha’s Vineyard saw another mechanical breakdown, triggering a fresh swirl of criticism and concern, including on social media.

The Monday staff summary acknowledges the many problems — including a communications system that is outmoded and unwieldy — and describes a complicated plan to solve them.

Apart from the extreme number of cancellations on the Vineyard route this year, a staff analysis also found an increasing pattern of cancellations due to weather conditions. As a result, new reporting procedures have been put in place for captains and terminal agents to keep better track of delays and cancellations.

The report also outlines a plan to improve communications, beginning with the hiring of a new communications director, who will be responsible for both developing and carrying out a comprehensive “improvement plan” to the SSA’s communications system.

Until the new communications director is in place, an array of staff responsibilities will be reassigned internally to better manage communication, including updates on the website, travel advisories and email alerts.

A new communications and operations center is proposed that would be housed in the recently completed administration building off Palmer avenue in Falmouth.

The report also proposes working with the Martha’s Vineyard Chamber of Commerce and hosting a public forum on the Vineyard to hear suggestions from Islanders. The forum is tentatively planned for June 5 at the regional high school.

Mr. Hanover said Monday that he still plans to press for outside review at the meeting on Nantucket next Tuesday.

“I believe the general manager and staff are doing all they can, but they don’t have the tools and I don’t believe they can solve this,” he said. “Somebody from the outside needs to be brought in.”