Nearly 25 years after the M/V Martha’s Vineyard began her daily seven-mile passages between Woods Hole and the Vineyard, the Florida-built Steamship Authority ferry is getting a $17.4 million, top-to-bottom makeover that’s designed to keep it plying the route for at least another quarter-century.

Passenger deck stripped to the studs. — Courtesy Steamship Authority

“The vessel was first placed into service back in 1993,” SSA general manager Robert Davis told the Gazette. “Since that time, it’s carried a lot of passengers and logged a lot of miles.” The ferry has traveled some 780,000 miles, he said.

The refurbishment has been underway since early September at Senesco Marine in North Kingstown, R.I. The work is designed to more than double the ferry’s lifespan, increasing it by 25 to 30 years, while improving passenger comfort and navigational safety.

After the Martha’s Vineyard arrived at Senesco, the ferry was boarded pierside by about 125 shipyard workers, SSA maintenance and engineering director Carl Walker told boat line governors at their monthly meeting in Oak Bluffs two weeks ago.

The Senesco crew’s first job was to saw off the ferry’s old pilot house and cabin, quickly adding a new, prefabricated pilot house with larger windows and smaller mullions designed to improve visibility for pilots.

The ferry then was moved into Senesco’s drydock, where workers stripped its decks to bare steel and found that more of the decking than expected was so corroded it had to be replaced. This additional work represents the lion’s share of about $1 million in change orders that have arisen during the refurbishment.

New pilot house put in place. — Courtesy Steamship Authority

“We have to do what it takes to make a 25-year boat,” Mr. Walker said. That includes new generators and electrical systems, remodeled decks, hull cleaning and replacing steel around the ferry’s windows.

Passengers and observers won’t see a radically changed vessel when the Martha’s Vineyard returns to service next year. Its length, beam and capacity — the freight deck holds up to 54 vehicles and there is lifesaving equipment for 1,280 people, Mr. Walker told the Gazette — will all remain unaltered. Even the new pilot house has essentially the same dimensions and profile as the old one, Mr. Davis said.

The most visible update is the new bow door: The Martha’s Vineyard is losing her old clamshell door for a horizontal roller door, like the one on the newer Island Home.

Another improvement: Travelers will no longer need to stand on the weather deck as they wait to disembark. “We’re extending the cabin on the 02 deck, where the lunchroom and the purser are, back to encompass where the stair towers are,” Mr. Davis said.

Work is taking place at Senesco Marine in North Kingstown, R.I. — Courtesy Steamship Authority

This change too is a subtle one. “For most people, they won’t even notice that until it’s raining and they realize they’re not standing out in the rain,” Mr. Davis said.

The Martha’s Vineyard is the third ferry the SSA has sent for a mid-life refurbishment since 2008-2009, when the 1974 M/V Nantucket went in for a makeover. The M/V Eagle, which has plied the Hyannis-Nantucket route since 1987, was updated next.

“We try to do these refurbishments in the 25-30 year range,” Mr. Davis said. That means the 11-year-old Island Home has a few years to go, he added.

The Martha’s Vineyard is scheduled to resume service on March 3, 2018.