Minor correction to Attila's last post. The IVLL is not produced by the CAA. It is produced by the UK North Sea helicopter companies (Bristow and Scotia). They finance the manpower to do helideck inspections, and collate all helideck info including voyage reports about turbulence etc. The end result is the Installation and vessel Limitations List (IVLL) which is available to our pilots during preflight planning and also in the cockpit. This allows us to be fully briefed on every aspect of a helideck prior to arrival. Gone are the days when one operator would impose a limitation on a deck due to a severe turbulence problem and no-one else would be told. All limitations etc are the same for each operator.