US Coast Guard resume search for Cheeki Rafiki life raft and sailors
by Rob Kothe, Sail-World.com on 20 May 2014
The British Prime Minister David Cameron has announced that the search for the four missing crew from the 40ft Cheeki Rafiki is to be resumed.
Hull sighting: On Saturday, a cargo vessel, the MV Maersk Kure, spotted and photographed an overturned hull, pictured, which matched the description of the Cheeki Rafiki but reported no signs of people on board Maersk Kure
The search was initiated after a request was made by the UK government.
Previously U.S. Coast Guard Capt. Anthony Popiel, chief of response for the first Coast Guard District, explained that the US Coast Guard had ended their search after 53 hours, based on a 20 hour survival time.
A spokeswoman for the US Coast Guard confirmed to the BBC that the 'planning process' for the renewed effort to rescue the men began just after 7:30 local time (12:30 BST).
'It'll be co-ordinated by air and sea as before but the details are still being worked out,' she told BBC News.
She said she could not at this stage say why the search had resumed. The coast guard had previously said it would only start searching again if new information came to light.
Aircraft are flying from North Carolina to the coastguard in Boston where they are expected to arrive later.
Apart from the huge pressure mounted via the 195,000 petitioners and a lot of very famous sailors, there is perhaps another reason buried in the initial Coast Guard statement.
Here is an extract of that statement: ' Seas were 15 feet with winds surpassing 50 knots. The air temperature was 59 degrees and the water was 60 degrees.
'When conducting extended searches, the U.S. Coast Guard uses a survivability model that takes into account weather conditions, emergency equipment, and the anticipated condition of the people for whom we are searching. Based on the extreme conditions at sea, but assuming best-case emergency equipment, the estimated survival time past the time of distress was approximately 20 hours. Crews searched for 53 hours.'
Its seems likely that a 20 hour survival time assumes the four British sailors were in the water, not in the 12 man life raft that the Beneteau First 40.7 Cheeki Rafiki was carrying.
Because a quick cross check with the survival charts more commonly used in the sailing community suggests that survival time assumes the four British sailors were in the water, not in the 12 man life raft that the Beneteau 40.7 Cheeki Rafiki was carrying. There have been many cases where sailors have survived in life rafts for weeks even months.
The U.S. Coast Guard has mandated the use of a highly sophisticated Probability of Survival Decision Aid (PSDA) predictive model in determinations of survival times in the water and it seems likely the quite short survival time has come from that software.
Now the USCG has been confronted with what the fact that time line is irrelevant if the Cheeki Rafiki four in 12 man raft?
We note that is not seriously addressed by the PSDA which does however note 10 days in a life raft as being quite possible?
Given the the long period in which the four British sailors knew the boat was in danger of sinking, its clear that they would have been wearing flotation devices and the life raft would be been on deck ready for deployment.
So now the USCG will put assets back into a search for the life raft and hopefully the four British sailors. The Australian Navy sent a warship 1300 nm to look for and find Tony Bullimore 500 nm from Antarctica, it should be possible to find closer ships in the mid-Atlantic.
We hope and pray the USCG and their searcher will be successful.
In the far less sophisticated data set, the survival time for a person in cold water is limited as indicated in the table below:
|70 - 80
||21 - 27
||3 - 12
||3 - unlimited
|60 - 70
||16 - 21
||2 - 7
||2 - 40
|50 - 60
||10 - 16
||1 - 2
||1 - 6
|40 - 50
||4 - 10
||0.5 - 1
||1 - 3
|32.5 - 40
||0 - 4
||0.25 - 0.5
||0.5 - 1.5
||< 15 min
||15 - 45 min
For the latest story and backgrounder, including graphic of the liferaft believed to have been deployed, see the BBC report click here
If you want to link to this article then please use this URL: www.sail-world.com/122328