British researchers are developing a new computer model to predict how long someone will survive when lost at sea, which will in turn determine when a search and rescue operation may be stopped.

The Search and Rescue Survival Model is being developed by the University of Portsmouth’s Sports Science and Mathematics departments and the US Coast Guard. It aims to support the US Coast Guard target of saving 93 per cent of victims annually – between 3000-6000 people – whose lives are in danger at sea.

“Using this new computer model will take pressure off humans making very emotional and sensitive decisions about when to end a search,” said Professor Mike Tipton, human and applied physiologist, from the University of Portsmouth.

“When the model predicts that a victim can no longer survive, the search and rescue team can stop or redeploy the search.

“It will ensure that Coast Guard personnel are not exposed to the high risks associated with search and rescue operations any longer than necessary and will also help to save time and resources,” he said.

The US Coast Guard currently uses a software system known as SAROPS (Search and Rescue Optimal Planning System) to calculate how far a person will have drifted and how large the search area should be.

Data such as wind speed, sea state and water temperature is entered into SAROPS along with information about the victim’s sex, height, weight and what they were wearing to determine exactly how the search should be conducted.

“Calculating survival time will add another layer to SAROPS; it will be able to predict not only where a search should be conducted but when it should be stopped,” said Professor Tipton.

Chris Turner, Ocean Engineer and Manager for the project for the US Coast Guard in Groton, Connecticut, sought the help of the university because of its international reputation for expertise in the area of survival in the sea.

“The University of Portsmouth has been able to tap into and analyze data held by the Institute of Naval Medicine and the Royal National Lifeboat Institution, both critical to the development of this survival model. To our knowledge no other similar repository of this information exists – even in the US.

“The development of this technology is very exciting. It will be trialled in American waters in late 2009 and once thoroughly tested, the aim is to roll it out to the whole of the US,”he said. See Dick Durham’s blog