OP
Eric Sedletzky
Contributor
You're not going to get sued by an instabuddy that the dive boat stuck you with.I do say exactly that. I don't want a ruined dive that I paid good money and traveled quite a distance for, and even worse accept liability for a stranger. In the US divers have been sued following an accident involving a random assigned buddy.
The crew may say you must take this person as your buddy but it can't hurt to argue the point even to the point of refusing to dive and demanding a refund.
You're not a pro under contract and getting paid. You didn't volunteer to be the IB's buddy or agree to be fully responsible for them, you're just another paying customer. If something goes wrong the operator will be sued not you. In fact you might even have a case against them since you were as much a victim as the IB.