One of the disadvantages of Offshore Life is usually the confined quarters you have to live in.

The same guys that you get in the helicopter with are the ones you'll be eating with, sleeping near to, working with or near to, taking your breaks with and so on. When all is well and everyone gets on the camerardery and craik can making the days and weeks fly by. You'll make new friends and contacts while earning decent coin.
On the other hand, you can get to a rig or vessel with people you absolutely do not get on with and would cross the street to avoid when on the mainland. While sociopaths and lunatics don't tend to work offshore (although some will slip through the net) the knuckle-dragging types can thrive offshore, especially during shutdown season.

On the whole though the knuckle-dragging term is a bit loose and free, some of the folk considered 'knuckle-draggers' aren't usually bad people but just like to be loud and jovial. Rough diamonds, center-of-attention folk who like the sound of their own voice yet are salty. Often a disagreement on something and an arguement might result in back-biting and gossip with the term bandied around.

The Scaffolders and platers are often unfairly labelled (tarred?) with this brush offshore, although to be fair they are often some of the roughest, toughest and hardest men offshore and are considered to have the most dangerous job in the North Sea (Drill Crews vie for this accolade too though).

Personality Clashes

If you are paired up with someone you absolutely cannot stand to be around then it's best to nip it in the bud ASAP. Tell your supervisor on the quiet you have a problem with the guy and request to be moved to work with a different squad. Be prepared for some waves though, the worse case scenario is for you to be booted off the rig and NRB'd, although this is unlikely unless the guy is in tight with the gaffer. Don't let the guy you have a clash of personality with know about this if possible, unless you want to give him a piece of your mind. A good gaffer will make it look like he's moved you because of an innocuous reason and the clash of personality may not escalate any further.