Each year amateur radio fanatics head to about 400 different lighthouses the world over, to communicate with each other.

The International Lighthouse Lightship weekend aims to promote the need for preserving the world's lighthouses and has been running for nearly a decade.

When the date happened to be scheduled for the same weekend as the famous Central Australian dry river boat race, the Henley on Todd Regatta, the Alice Springs Amateur Radio Club came up with an idea.

They would build their own lighthouse and set up a radio station to communicate with all the others from the banks of the Todd River.

Organiser Greg Mair says they connected with people in over 40 countries from their lighthouse.

"We've made about 70 different contacts so far, communicating with like-minded ham radio operators in the Canary Islands, the Pacific, the Cook Islands, right round the Australian coastline and into Europe, with Spain and Portugal," he said.

"A lot of people have heard of the Henley on Todd Regatta but aren't sure where it is, so we promote it a bit."

Considering their lighthouse was thousands of kilometres from any coastline, Mr Mair said they got some interesting responses from across the world.

"Mostly they think we're bloody idiots!" he said.

"But they think it's very unique. And we've got a unique opportunity to get involved with the coastlines."

The Henley on Todd Regatta is a Rotary fundraising event that's been running for more than 50 years.

It's is Central Australia's answer to the Henley-on-Thames boat races in London.

Teams race bottomless boats and miniature yachts up the dry river bed. The finale is a battle between the Navy, Vikings and Pirates.

And with the lighthouse nearby, there was no risk of them accidently running ashore,

Mr Mair says the Alice Springs Amateur Radio Club were transmitting from the event mostly on high frequency bands.

"We're using the ionosphere, the layer between earth and space the bounce the signal off to get our messages out across the rest of the world," he said

"We use various aerials, from copper wire aerials to direction aerial - which is like a television aerial on steroids."

With more than 3 million licensed HAM radio operators the world over, Mr Mair says it's a tight-nit community.

"It's a hobby. A lot of people develop good friendships," he said.

"People use ham radios through their whole life.

"As they get older and their partners die they stay in touch with people they've been talking to for many many years.

"That's their source of communication and they have hundreds of friends the world over."