As early as Sunday afternoon, boaters were already planning ahead for a possibly precarious weekend of storm activity brought on by Henri — which was originally predicted to hit Rhode Island this weekend as a Category 1 hurricane, the first in 30 years to threaten the region since Hurricane Bob in 1991.

Under a cloudy blue sky, some large vessels could already be seen anchored on the placid waters of Kickemuit River as early as Friday afternoon in anticipation of the storm.

“Historically, the Kickemuit River has been used as a safe harbor area for major storms due to its protection from open waters,” said Ed Cabral, Warren’s harbormaster. Mr. Cabral reported on Monday morning that between 25 to 30 boats sought shelter on the Kickemuit River during the storm.

For Fred Massie, Warren Planning Board Chairman and an avid Mt. Hope Bay kayaker, there is no better place he is aware of in the region to anchor a boat during a large storm event. He says that tall shores on all sides of river, combined with its natural geographical positioning and a sufficient depth — combined with a sandy bottom — combine to make the river a natural storm buffer suitable for even large vessels to ride out a significant weather event.

“It’s also a destination for a lot of folks throughout the summer because it is so well protected. We get visitors from all over the east coast coming in,” Mr. Massie said on Friday. “I expect there will be a parade of boats coming in there. It’s a wide river at that point, there’s quite a bit of room for boats.”

The fury of Henri turned out to be less than predicted, and it was downgraded to a tropical storm and petered out quickly once making landfall. Mr. Massie reported on Monday that all boats held anchor on the Kickemuit River and no damages were reported.

Although he made it clear that he always thought it was wise to be better safe than sorry, Mr. Massie made a prescient observation on Friday.

“Weather forecasting has been about 50 percent correct for the last 100 years. In spite of all the technology we have, particularly around here, it’s still something of a guessing game,” he said. “We can put a man on the moon but we can’t figure out two days before whether or not a hurricane is going to hit.”