Survival suits don’t appear to be standard issue for these overwater jaunts?
Unheard of, oil industry operator was of the belief, erroneously, that folk could be rescued before hypothermia would raise its head. Logistics, and more importantly cost, seemed to put the kibosh on any suggestion of supplying suits. If you look at the report on the Wessex ditching linked earlier it says,
Even though they were in the water for no more than 25 minutes there is evidence to suggest that symptoms of hypothermia were beginning to set in
And that was in December, summer time.