Fast ferries have been much in the news these days, especially on the Vineyard, but here is a fresh question to ponder: What happens when a ferry that plies what is arguably the shortest route in the world suddenly becomes faster?

Of course the answer is simple enough - the ferry gets there faster. On the Chappaquiddick ferry this means a route that now takes about two minutes has now been shortened by about 30 seconds.

But in fact ferry owner Roy Hayes says speed was not the main motivation when he recently replaced the engine in the On Time 3, one of two three-car barges that operate as the Chappaquiddick ferry.

Mr. Hayes says they no longer make the old 135-horsepower Ford diesel engine that has propelled the On Time 3 for the last 10 years.

So Mr. Hayes replaced the old Ford with a new John Deere 225 horsepower engine.

"I've been debating this for a couple of years; parts were becoming very expensive and I've already rebuilt the engine once," says Mr. Hayes, who does nearly all of the maintenance on the ferries himself. He says the Chappy ferry, which runs every day of the year across the narrow channel that is the entrance to the Edgartown harbor, logs about 53,000 hours annually. Mr. Hayes is accustomed to rebuilding the engine every 25,000 hours.

The new John Deere engine is not only faster but it's also more fuel efficient. "We are burning a third less fuel than we did before," Mr. Hayes says.

But he says the real reason more power is important on the Chappy ferry is not speed, but maneuverability in wind and strong tides. "We should be able to operate better in severe weather because it gives us more push - you need a lot of power to turn that boat against a hard-running tide in a northeast wind," Mr. Hayes says.

Mr. Hayes says the four regular captains are happy not only with the new power but with the new noise - or make that a lack of noise. The new John Deere engine is noticeably more quiet than the noisy old Ford. "The captains really enjoy it, they are very, very happy with it," Mr. Hayes says.

The engine conversion cost about $30,000. The work took about five days with a small crew led by Mr. Hayes.

"It's just reliability and comfort and a little more power when you need it - it has nothing to do with getting more trips in," Mr. Hayes says. "We actually need the power off-season when the weather turns bad."

Numbers tell a good part of the story. The Chappaquiddick ferry travels a route that is 572 feet across the channel. During a short and informal timing exercise on board the ferry this week, the fastest time logged was 58 seconds at slack tide on an empty ferry with Capt. Kim Morse at the helm. The longest time logged was 87 seconds with two cars on board at mid-tide with Capt. Charlie Ross at the helm. A middle time of 66 seconds was logged at slack tide with two cars on board and Capt. Robert Gilkes at the helm.

Unfortunately the random timing exercise missed all the shifts of Capt. Brad Fligor. And for the record, Captain Morse obliged a request for more speed and opened up the throttle a little, while Captain Ross reacted somewhat mischievously to the same request, pulling back on the throttle to slow the boat down a little.

Using the time recorded during Captain Morse's shift, the speed of the newly powered Chappy ferry is 5.84 knots, or 6.724 miles per hour, or 118.27 inches per second. Mach speed is 0.009.

"We haven't ever really opened it up," Captain Morse confesses.

Captain Ross refused a request for a cruise to Cape Pogue.

Does this mean the Chappy ferry is now fast enough for water skiing?

Mr. Hayes just laughed.