From "Message in a Bottle," a Wikipedia article. Lots more message-in-a-bottle stories at that link. Examples:
In December 1928, a trapper working at the mouth of the Agawa River, Ontario, found a bottled note from Alice Bettridge, an assistant stewardess in her early twenties who initially survived the December 1927 sinking in a blizzard of the freighter Kamloops and, before she herself perished, wrote "I am the last one left alive, freezing and starving to death on Isle Royale in Lake Superior. I just want mom and dad to know my fate."...The longest time between a message sent and when it was received, as far as we know, is 151 years. A seaman named Chunosuke Matsuyama sent a message from an island in the Pacific in 1784. It was found in Hiraturemura, Japan in 1935.
In 1956, Swedish sailor Ake Viking sent a bottled message “To Someone Beautiful and Far Away” that reached a 17-year-old Sicilian girl named Paolina, sparking a correspondence that culminated in their marriage in 1958. The affair attracted so much attention that 4,000 people celebrated their wedding.
The message in a bottle is a popular theme. There's Edgar Allan Poe's story "MS. Found in a Bottle" and there's The Police song "Message in a Bottle":
I'm reading that Wikipedia page after clicking over from "Beachcombing," which turns out to be an extremely interesting subject: