Each year on her birthday, Ann Hernandez and her boyfriend, Alan Tomaska, would settle on the rocky shore of Thacher Island and uncork a bottle of champagne in a toast to the day. When the bottle was empty and the tide going out, Hernandez would tuck a handwritten message inside and Tomaska would hurl the bottle over the rocks and into the crashing surf.

Tomaska considered the ritual a lark.

But for Hernandez, the messages in a bottle were a kind of personal driftwood - a piece of her joining the sea and traveling with its currents to hoped-for far-flung locales.

“When we got back to our humdrum lives, we didn’t talk about the bottles,’’’ said Tomaska, a home remodeler. “But whenever we were on the island, she would say, ‘One of these days, someone is going to find one of those bottles.’ ’’

It would take six years, but someone did. Defying nautical laws and odds, one of Hernandez’s bottles last month bobbed along the coast of France to a quaint village, where a French couple, Michel and Daniele Onesime, scooped it out of the water and read with wonder the note inside.

“While we were setting out to go deep-sea fishing one morning from the port at St. Gilles Croix de Vie, on the Vendee coast, my wife and I found a white glass bottle floating by,’’ Michel Onesime wrote in an e-mail to the Globe. “The moment we plucked it from the water, we saw that there was a message inside.’’

The message read: “Ann Hernandez is a lighthouse keeper on Thacher Island - Cape Ann Light Station and had a birthday there Oct 10 2003. Drop her a card at home.’’ The message included her year-round Illinois address. The Onesimes quickly jotted a postcard and sent it off.

But the connection was not to be.

The postcard came back to them marked undeliverable. When the couple sent an e-mail to the Thacher Island Association, it reached its president, Paul St. Germain, who relayed sad news. Hernandez unexpectedly died at age 61 from complications of surgery the day before Thanksgiving last year.

Since then, the Onesimes have joined in mourning Hernandez and found themselves linked to her friends and loved ones - a connection forged, in this age of instant communication, not through text message, not through e-mail, but through a bottle that withstood a 3,000-mile trip across the ocean.