Let me also give an example, from a dive operator's point of view. A few years ago I had an extended family group diving with me. Seven people if I remember correctly, three generations and three vertically (ie three siblings and families).
My standard registration form asked for details of insurance. I required it for tech divers, but only recommended it for rec divers such as these. Every member of the group had cover (all DAN I think, but there are others) except the group leader, the only man with kids in the group.
Anyway, they were all experienced and good divers and had been diving with us for a few days, so we were pushing more towards the edge of the envelope as that's what they wanted. Still well within no-deco limits mind. At the end of the first dive one morning the DM had completed the safety stop and was just starting the final ascent to the boat. This man, who was an avid photographer, spotted several eagle rays on the bottom 70ft below, and went straight down to them. The DM (who is now a renowned local instructor, despite being very young) sent his wife & kids and the rest up to the waiting boat and stayed at 15ft watching the photographer. After he'd fired off a few snaps he rocketed back up towards the boat. The waiting DM stopped him and held him there, very much against the photographer's will, for over 10 minutes, then surfaced for the boat. The man was mildly annoyed at what had just happened and clearly didn't appreciate why the DM had behaved in that way. He insisted he was fine, and the DM didn't see anything untoward, so when the boat went out again an hour later the photographer was on it.
After lunch he (the photographer) was walking along the beach with his 12-year old daughter who had been in the dive group when he suddenly collapsed unconscious. Luckily Belize's only recompression chamber is here in San Pedro and it took maybe 20 minutes to get him there. I knew none of this, as I was elsewhere on the island doing something else. I had a call from the chamber several hours after he was admitted, and went there when his first course of treatment was due to end. That's when I found out all the above, from his wife and my DM.
When the man emerged from the chamber he looked terrible, with a bubble on one eyeball that was bigger than the eye itself. He was in a lot of pain from joint bends, and his skin was crackling like a crisps packet. I talked with him and he was a changed man, deeply apologetic. His wife showed him scant sympathy.
To cut a long story short, he had repeated treatments over the next eight days, and was then discharged. He wasn't allowed to fly for at least another three or four days, and then only when a certificate had been issued by the chamber.
Throughout all this time his family stayed close by, though they had to move hotels as theirs was fully booked after their prebooked term had expired. Obviously all flights had been cancelled and not rebooked because no-one knew when he'd be ready to fly.
As he didn't have any dive insurance he had to pay the lot. I participated in a scheme to support the chamber financially which meant that their charges for my divers were capped, but even so he was charged US$35k for chamber and all his medical costs. Add to that the cost of cancelled flights and almost two weeks of additional hotel accommodation for 7 people and you can see that for him it was a VERY costly mistake not to have insurance. US$65 spent on DAN cover as I had recommended would have meant that most if not all of these costs would have been covered.
If he had been diving elsewhere in the country, at least several hours away from the chamber, it was the view of the senior doctor that he might not have made it at all. So there are two lessons here - GET INSURANCE and DIVE CONSERVATIVELY, or at any rate not stupidly, bearing in mind what medical support is available to you.
