What is believed to be the world's oldest discovered message in a bottle has been presented to the sender's granddaughter, 101 years after it was first tossed into the sea in Germany.

People have been putting messages in bottles for much longer than a century: in 310 BC, Greek philosopher Theophrastus put sealed bottles into the sea as part of an experiment to prove the Mediterranean Sea was formed by the inflowing Atlantic Ocean.

Oceanography is a common reason drift bottles are thrown overboard, but there are also some romantic and surprising stories of sending messages across the sea throughout history.

Here are 10 of the most famous floating note discoveries:

1. A new world record?

FOUND BY: Konrad Fischer in the Baltic Sea, 2014

SENT FROM: Richard Platz in the Baltic Sea, 1913

TIME AT SEA: 101 years

A message in a bottle tossed in the sea in Germany 101 years ago, believed to be the world's oldest, was presented to the sender's granddaughter, a Hamburg museum has said.

A fisherman pulled the beer bottle with the scribbled message out of the Baltic Sea off the northern city of Kiel in March, Holger von Neuhoff of the International Maritime Museum in the northern port city of Hamburg said.

Mr Von Neuhoff said researchers were able to determine, based on the address, that it was 20-year-old baker's son Richard Platz who threw the bottle in the Baltic while on a hike with a nature appreciation group in 1913.

Fisherman Konrad Fischer holds a bottle which contains a message from 1913, that he pulled from the Baltic Sea. ( AFP: Uwe Paesler )

2. Floating on North Sea currents

FOUND BY: Scottish skipper Andrew Leaper near the Shetland Isles, 2012

SENT FROM: Captain C. Hunter Brown near the Shetland Isles, 1914

TIME AT SEA: 97 years and 309 days

A drift bottle released out to sea on June 10, 1914 by Captain C. Hunter Brown was recovered by UK fisherman Andrew Leaper almost 98 years later, on April 12, 2012.

Brown was a scientist at the Glasgow School of Navigation studying the currents of the North Sea, and the bottle was one of 1,890 released on June 10, 1914.

It is the current Guinness World Record holder for oldest message in a bottle.

The message inside read: "Please state where and when this card was found, and then put it in the nearest Post Office. You will be informed in reply where and when it was set adrift. Our object is to find out the direction of the deep currents of the North Sea."

The bottle was discovered 9.38 nautical miles from the position it was originally deployed.

3. Jonathan to Mary

FOUND BY: Matea Medak Rezic in Croatia, 2013

SENT BY: Jonathon (identity unknown) from Nova Scotia, Canada, 1985

TIME AT SEA: 28 years

A 23-year-old kite surfer, Matea Medak Rezic, stumbled across a half-broken bottle while clearing debris from a Croatian beach at the mouth of the Neretva river in the southern Adriatic.

It is not known where Mary is from, or how she knew Jonathan. ( Facebook: Matea Medak Rezic )

Inside the bottle was a message from Jonathan, from the Canadian province of Nova Scotia, who had written it 28 years earlier, honouring his promise to write to a woman named Mary.

The message reads: "Mary, you really are a great person. I hope we can keep in correspondence. I said I would write. Your friend always, Jonathon, Nova Scotia, 1985."

The bottle would have had to have travelled approximately 6,000 kilometres across the Atlantic Ocean, entered the Mediterranean Sea, and then drifted into the Adriatic Sea.

Jonathan and Mary's identity, and how the two knew each other, is unknown.

4. Writing to Zoe

FOUND BY: A Dutch couple in Oosterschelde, Netherlands, 2013

SENT BY: Zoe Averianov, from a ferry travelling from Hull to Belgium, 1990

TIME AT SEA: 23 years

Zoe Averianov, from Hebden Bridge, was 10 years old when she threw her message in a bottle overboard as she went on holiday, travelling by ferry from Hull in England to Belgium on September 12, 1990.

Her message read: "Dear finder, my name is Zoe Lemon. Please would you write to me, I would like it a lot. I am 10 years old and I like ballet, playing the flute and the piano. I have a hamster called Sparkle and fish called Speckle."

Twenty-three years later at Christmas in 2013, a letter arrived to Zoe's parents' address from a Dutch couple: "Dear Zoe, yesterday on one of my many walks with my wife along the dikes of Oosterschelde looking among the debris thrown by the sea of embankment I found a little plastic bottle containing your message."

5. A mother to her son

FOUND BY: Karen Liebreich and Sioux Peto on a beach in Kent, 2002

SENT BY: An unnamed French mother from a ferry crossing the English Channel, 2002

TIME AT SEA: A few weeks

In 2002, while on a ferry crossing the English Channel, a French mother threw a teardrop-shaped bottle, some clothes and lilies overboard.

Inside the bottle was a note from the mother to her child, Maurice, who had died at age 13: "Forgive me for being so angry at your disappearance," the letter went. "I still think there's been some mistake, and I keep waiting for God to fix it … Forgive me for not having known how to protect you from death. Forgive me for not having been able to find the words at that terrible moment when you slipped through my fingers".

A few weeks later, Sioux Peto found the bottle washed up on a beach in Kent when she was walking her dogs.

Peto found a lock of hair and a letter written in French inside. She gave the letter to her friend, UK-based author Karen Liebreich, to translate.

Over the following few years, Liebreich tried to discover who the French mother was, but without success.

Then in 2006, Liebreich authored the book The Letter In The Bottle about the discovery, and a few years after the book's release, the mother who wrote the letter contacted Liebreich and the two women finally met a month later in northern France.

6. A grandson's connection

FOUND BY: Geoff Flood at Ninety Mile Beach in New Zealand, 2012

SENT BY: Herbert Hillbrick from an unknown location, but thought to be from a ship travelling from England to Australia, 1936

TIME AT SEA: 76 years

Geoff Flood was taking a walk with his partner on Ninety Mile Beach in New Zealand one Sunday in November 2012, when he noticed a bottle floating near the beach.

Inside the bottle he found a handwritten note dated March 17, 1936: "At sea. Would the finder of this bottle kindly forward this note, where found, date, to undermentioned address."

Underneath the note was signed the name: "H E Hillbrick, 72, Richmond Street, Leederville, Western Australia."

The note was written on special stationery marked with a picture of the ship that the note is thought to have come from - the SS Strathnaver, a British Royal Mail Ship that carried people between England and Australia.

Flood discovered that H. E. Hillbrick had died in the early 1940s, but he was lead to Hillbrick's grandson, Peter Hillbrick, who was living in Perth.

Peter told local media of the discovery: "The only connection I have with Grandfather is now that bottle. That's about all. So, it's a fascinating story."

7. From five-year-old Frank

FOUND BY: Daniil Korotkikh on the Curonian Spit in Lithuania and Russia, 2011

SENT BY: Frank Uesbeck from a ship travelling to Denmark, 1987

TIME AT SEA: 24 years

Daniil Korotkikh, a 13-year-old Russian, was walking with his parents along a beach on the Curonian Spit when he saw what he said looked like a German beer bottle with a ceramic plug lying in the sand.

Inside he find a message written in German. Korotkikh's father knew some German and translated the letter. It said: "My name is Frank, and I'm five years old. My dad and I are travelling on a ship to Denmark. If you find this letter, please write back to me, and I will write back to you."

The five-year-old boy who wrote the letter is, Frank Uesbeck, who was 29 when the message was discovered.

Korotkikh and Uesbeck met each other via an internet video link in March, 2011.

8. Across the Atlantic

FOUND BY: Breda O'Sullivan in Dingle, Ireland, 1946

SENT BY: Frank Hayostek, 1945

TIME AT SEA: Eight months

Frank and Breda exchanged letters back and forth across the Atlantic for seven years.

On Christmas Day in 1945, a 21-year-old American World War II veteran, Frank Hayostek tossed a bottle over the side of his troop carrier with a note tucked inside.

Eight months later, the bottle was found on a beach near Dingle in Ireland by 18-year-old milk maid, Breda O'Sullivan.

What followed was seven years of letters exchanged back and forth across the Atlantic between them.

The two finally met in August 1952 when Hayostek had saved enough money to fly to Ireland amid an international media circus over the story, but the pair were never able to get their romance off the ground.

9. Escaping a regime

FOUND BY: Hoa Van Nguyen off the coast of Thailand, 1983

SENT BY: Dorothy and John Peckham from a cruise to Hawaii, 1979

TIME AT SEA: Four years

In 1979, during a cruise to Hawaii, Dorothy and John Peckham wrote notes and placed them inside empty champagne bottles, then threw them overboard.

They wrote asking anyone who found the message to get in contact with them, and they included a $1 bill in each to cover postage of the reply.

In 1983, the Peckhams got a response. Hoa Van Nguyen, a former soldier in the Vietnamese Army, had written them a letter saying he and his younger brother found one of the bottles while floating off the coast of Songkhla Province in Thailand in an attempt to escape the communist regime in Vietnam.

The Peckhams exchanged letters with Van Nguyen, and when Van Nguyen asked whether the couple could help his family move to the United States, they worked with US immigration to make it happen.

The families finally met in 1985 when Van Nguyen flew into Los Angeles from Thailand.

10. A British soldier on the way to the front

FOUND BY: Steve Gowan on the Essex coast, England, 1999

SENT BY: Private Thomas Hughes when he tossed it into the English Channel, 1914

TIME AT SEA: 85 years

In 1999 while fishing off the Essex coast in England, Steve Gowan found a green ginger beer bottle with a screw-on stopper.

Inside, Gowan found a message from 26-year-old World War I soldier Private Thomas Hughes to his wife, with a covering note for the finder of the bottle.

The bottle had been tossed into the English Channel as Hughes left to fight in France.

The covering note read: "Sir or madam, youth or maid, Would you kindly forward the enclosed letter and earn the blessing of a poor British soldier on his way to the front this ninth day of September, 1914. Signed Private T. Hughes, Second Durham Light Infantry. Third Army Corp Expeditionary Force."

The letter read: "Dear Wife, I am writing this note on this boat and dropping it into the sea just to see if it will reach you. If it does, sign this envelope on the right hand bottom corner where it says receipt. Put the date and hour of receipt and your name where it says signature and look after it well. Ta ta sweet, for the present. Your Hubby."

Two days after writing the letter in 1914, Hughes was killed.

The family later moved to New Zealand, where Gowan was able to deliver the letter to Hughes's daughter, Emily Crowhurst, 85 years later.