A mobile data system supplied by Tait will improve the speed and efficiency of marine rescues for Sumner coastguards in New Zealand.

Featuring GPS-based automatic location equipment, the system enables search organisers to monitor and plot the movement of rescue vessels on a computer.

The precise location of each boat is polled automatically every 30 seconds, or manually at other times if required, and transmitted back to the Coastguard base where it is displayed as an icon of the boat on a map on the computer screen.

Knowing the exact location of each rescue vessel helps search organisers to despatch the most appropriate boat or organise an accurate grid search. It also improves safety for Coastguard staff.

In the past the Coastguard has relied on voice contact over a VHF radio system for the reporting and despatching of search co-ordinates.

'But our fast response boat has a top speed of 38 knots,' says Sumner Lifeboat Coxswain, Paul Lawson. 'It's almost impossible to do chartwork at that speed and we virtually have to stop the boat to get accurate GPS co-ordinates.'

The new Tait system enables the despatch of text messages, such as search instructions, to a mobile data screen on the boat. A search organiser, watching the rescue boat's 'snail-trail' across the computer screen, can also use the VHF radio to guide the boat in the appropriate direction.

'In marine rescues the 'golden hour' principle applies,' says Paul. 'Equipment like this helps us provide the fastest, most effective response, which is critical when a person's chance of survival in the water diminishes greatly after the first hour.

'We see this as quite exciting for marine search and rescue. Not just because of the functionality available now, but because of the future potential to develop the system further.'

Future options include the overlaying of sea current and tide data to further take the guesswork out of searching, or adding recreational or commercial vessels to the system so if someone reported a boat overdue on a trip the Coastguard could poll it for its GPS location and direction.

Tait Communications Christchurch Branch Manager Matthew Beaven says the system is a highly cost effective mobile data option for marine rescue.

'Comparable systems cost hundreds of thousands of dollars,' says Matthew. 'We realise funding is often tight for search and rescue organisations so we've been able to make this cost effective by using standard AutoTrack Xpress mapping software developed by WirelessData, a company we partly own.'

All nine rescue vessels in the Canterbury Coastguard alliance are being fitted with GPS units connected to trunked T2000 mobile radios (connected to the Teamtalk Fleetlink mobile radio network). The equipment is being installed in the boats in rugged, watertight plastic cases.

When each vessel is polled, the GPS location is automatically transmitted through the trunked mobile radio network to the search headquarters where the AutoTrack Xpress software on the computer displays the information on a map.

While each rescue vessel will continue to use the Coastguard's VHF radio equipment, the Tait solution also provides back-up voice communications, including the ability to use the Tait radio to place and receive telephone calls.

The nine local rescue vessels cover more than 400kms of coastline. Last year the alliance was involved in about 350 incidents.

The Royal New Zealand Coastguard Federation expects to rollout the system to at least five other areas once it has been successfully adopted by the Canterbury region.

Read more information about mobile radio networks.