Jetty No. 6

Court Street groin.

Like the giant teeth of a sand comb, a series of 26 stone jetties — more accurately called groins — rake the beaches of Provincetown Harbor. They were constructed from 1939 to 1940 at a total cost of $30,000 (about $550,000 in today’s money). The Town chipped in 25 percent. Barnstable County and the Commonwealth of Massachusetts picked up the rest of the tab. The East End groins were built first, by Louis Byrne of Dennis. The Speedway Construction Company of Boston built the second group, in the West End. Each was originally 125 feet long, 12 feet wide, and 3 feet high. Many of the stones used for these groins came from Quincy, which was the source of the boulders used in the enormous West End Breakwater. This particular groin, near the foot of Court Street, was designated Jetty No. 7 in 1939 by the state Division of Waterways.

Groins are designed to mitigate the drift of sand along a beachfront. As far as their many critics contend, they do their job all too well. They create curving pockets along the shoreline as sand erodes from the leeward side of one groin and is deposited against the windward side of the next groin along.

They can be a bit perilous, too. “My aunt used to take us to the Court Street beach,” Lisa King recalled in a Facebook comment thread on 17 January 2021, responding to this article. “I fell on that jetty and cut my arm open once. I also stepped on a nail there.”

Gambols on the groins were officially banned in 1953 by the Massachusetts Division of Beaches, in Chapter 666 of the General Laws: “Climbing upon or over or walking along breakwaters, jetties, or groins is prohibited.”

There are other perils, according to the Provincetown Harbor Management Plan Amendment of 2018. “Groins become navigational hazards when they become submerged at high tide,” the plan stated. “Proper marking can prevent accidents.”

To the extent they have preserved property owners’ beachfronts, however, the groins are considered a success.

“Without them, a lot of houses and buildings along Commercial Street would soon be gone, because their exact purpose is to stop the natural erosion of sand,” the fisherman Wayne Martin said on 17 January 2021. “Look what happened to Herring Cove right after they removed all the ones that were there. Did you think they were placed there because they were aesthetically pleasing, or for little kids to climb on? Also, what type of vessels travel that close to shore along that stretch of beach at a rate of speed that it would be considered to be a ‘navigational hazard’? To do so would be idiotic, not to mention illegal.”

A typical section of a groin (or jetty), from “Proposed Shore Protection Provincetown,” September 1939, Division of Waterways, Department of Public Works of Massachusetts. In the Provincetown Building Department archive.