While searching through the various video forums for a few videos on commercial divers, I came across a pretty good one which will give you a hint of what one faces offshore.
You can go to school all you want but until you actually get offshore - to smell the atmosphere of diesel generators, aviation fuels, salt air and the wind - you will not quite "get it". This little video I found on YouTube will give a smattering of what its like. And for those that have been there - a reminder of why you like it - or don't!
As they say ... there is no life like it!