The Marine Park Green Zone Proximity Alarm is being developed by Atherton Tableland Geographic Information Systems "@GIS."

@GIS information technology manager Guy Carpenter said commercial fishers had approached the mapping organisation because they feared fines or possibly confiscation of their boats if they strayed into the no-fishing zones.

"Even with modern navigational gear, they're often down the back of the boat working and unaware of exactly where they are," Mr Carpenter said.

"The fishers asked for some sort of alarm to alert them when they're within a specified range of green zones."

"The fishers using the Green Zone Proximity Alarm won't have to be in the wheelhouse for them to know when they are approaching no-fishing areas."

@GIS combines reef mapping and global positioning system programs into a computer about the size of a car radio which can sound an alarm or trigger warning lights to alert fishers.

A prototype has been built and testing is under way. Mr Carpenter said he expected units to be available in December for less than $3000.

Mr Carpenter said maps issued by the Environmental Protection Agency and the National Parks and Wildlife Service contained warnings that they did not consititute a defence if they guided fishers into no-go areas.

"This new technology will take the guesswork out of it," he said.