Just why are you flying in excess of the certification level of your emergency float system on the aircraft
A very good question, and one that has been raised many times by myself and others. No sufficient answer is given, so let us put it down to commercial pressure.
The problem really is that it is not a limitation, and nowhere in the OMs nor in JAR-OPS does it state that one cannot fly when the sea state is greater than the certified level of flotation system. Unless OMs are watertight, so to speak, common sense will not always prevail. Holes will always be exploited by those more concerned with money than safety, and this includes the customers as well as management. The only thing likely to stop an operation will be when it is acknowledged that there is no rescue capabilty available, and this is not always completely apparent until a switched on captain raises the question.