Whats it like to work offshore on an oil rig in the UK area please?

I know the moneys good but what are the downsides?Whats it like to work offshore on an oil rig in the UK area please?
It's stating the obvious, but I know someone that does it in the US anyhow...they have no family time really being out on the ocean for the bulk of the time. In addition it can result in lots of moving depending on where you're sent I've heard...but I know also you can settle down and work within region. Unfortuately I can't be a big help...but I can say it is very time consuming...