For many Cold War escapees in the former East Germany, electrified fences, minefields and booby traps stood in the way of freedom. But for two surfing mates it was the icy Baltic Sea that stood between them and freedom.

Thirty-one years ago East Berliners Karsten Klünder and Dirk Decker, were in the midst of a daring and ingenious escape bid from behind the Iron Curtain - by windsurf boards.

The two friends had decided to risk drowning and capture by windsurfing 70 kilometres aboard their specially-built crafts to Denmark.

Jesper Clemmensen, a Danish journalist and author of the book Escape Route: Baltic Sea , told Nine.com.au the pair’s audacious voyage was driven by boredom with East Germany’s rigid communist system.

Karsten Klunder sailing a windsurf board. (Photo: Facebook).

“They were fed up with the system in the German Democratic Republic, and in particular the travel restrictions, that made it impossible for them to explore the western part of Europe.

“The wanted to climb and hike the Alps and see other parts of western Europe and that simply wasn’t possible.”

Klunder and Deckert chose the Baltic Sea route because they feared the heavily guarded East German land border, known as the Iron Curtain.

Brandishing minefields, electrified fences, machine gun posts to deter escapees it had divided Soviet-controlled eastern Europe since 1945.

“Since they were trained surfers, the Baltic Sea seemed like a good idea,” said Clemmensen.

But with a sea temperature of just a few degrees above zero, strong winds and wickedly deceptive currents, it posed its own unique dangers.

East Germany's heavily fortified land border. (Photo: AP).

“It was extremely risky. The Baltic Sea has a low level of salt, which means that the waves rise faster and the current is stronger,” said Clemmensen.

Although they were experienced windsurfers their boards’ weight made them unsuitable for the 70km voyage to freedom.

With the help of a West German windsurfing magazine and a relative who worked as a sailmaker, Klunder and Deckert had adapted their crafts.

But even before they entered the water, they had to find a launch site.

“Although the coastline wasn’t as heavily guarded as the land border or Berlin, it was under constant surveillance and surrounded by restrictions,” Clemmensen told Nine.com.au.

“There were 900 soldiers on duty 24/7 who walked the coast all the time. This meant an escapee had to search and wait for an ‘opening’.”

On the night of November 24, 1986 in the waters off the island of Hildensee in East Germany, Klunder and Deckert found one.

East Berliners Karsten Klunder and Dirk Decker were bored with the communist regime in East Germany. (Photo: AP).

Their departure point made their journey about 30kms longer than the shortest sea crossing between the communist state and Denmark, but they believed it to attract fewer naval patrols.

But there were still risks. Would there be enough wind to give their sails enough speed? Could they evade the patrol boats?

Klunder made good progress, sailing up to speeds of 33knots until he reached the Danish island of Mon after about seven hours.

But disaster struck Deckert when he ripped his wetsuit shortly after entering the sea. Realising it could spell death for him if fell into the icy waters, he made his way back to shore.

The following night he set out again with a new wetsuit. After six hours on the dark and cold Baltic he spotted a Danish trawler.

“Are you Dirk?” a voice yelled out to the surprised windsurfer.

After Deckert’s failed attempt, the pair had become separated off the rough seas of Hildensee and Klunder had pressed on and had warned Danish fishermen to expect another brave windsurfer.

Years later after the fall of the Iron Curtain in 1989, Deckert revealed: "if I had known that the wall would fall three years later, I would have stayed. Definitely."