Originally Posted by Leapy
I emailed Crewsaver for their view on this...which is, that a Crewsaver 150N lifejacket is good with their drysuits. Quote from Crewsaver "We suggest 275N jackets for Ocean going and when wearing many layers of foul weather gear"
I agree with the Crewsaver suggestion that a 275N jacket is appropriate for ocean-going and when wearing many layers of gear, and I'll stand by my view that it is also appropriate when wearing clothing that provides additional buoyancy.
I think that most people would agree that Mike Tipton of the University of Portsmouth is generally recognised as the UK's prime authority on survival at sea, and his work on understanding why we have too many immersion deaths resulted in his view that it is because of:
- poor knowledge and understanding of the hazards, resulting in poor standards and inadequate equipment
- inadequately prepared and equipped individuals
- design and integration of PPE
- unrealistic testing of equipment resulting in over-estimation of performance (how many people know that tests are normally conducted by the manufacturers in relatively warm and calm indoor pools, with unclothed or normally clothed subjects?)
Tipton reminds us that "it has been known for many years that the buoyancy distributed throughout immersion suits can negate some of the beneficial characteristics of a lifejacket". In fact, the degree of variability of performance in the equipment tested was as much as 10-fold)
The recent investigation into the tragedy of the Ouzo found that although all three of the yachtsmen who died were wearing lifejackets, 2 were found drowned with their heads submerged, suspended by the armpits from the waiststrap of their LJs which were not fitted properly. In the 3rd victim the LJ fitted better but was still found floating nearly vertical with his airway submerged.
Our experience with simulating unconscious casualties has been that a 150N jacket cannot be guaranteed to turn the casualty face up with airway clear of the water when the wearer is dressed in a drysuit or floatation suit