If you ever do anything "risky" you'll fill out a similar form. Go look into skydiver liability forms, they also mention the possibility of death or injury. I suspect most people embarking on expensive & risky adventures are used to these and based on previous adventures being alright just sign the paperwork without reading or thinking about it deeply.
>2. A portion of the operation will be conducted inside an experimental submersible vessel. The experimental submersible vessel has not been approved or certified by any regulatory body and may be constructed of materials that have not been widely used in human occupied submersibles.
From that link, they characterized the severity (death) but not the probability. Saying "you may die" is different from saying "your have a 50% chance of dying." My guess is nobody had a good estimate for the probability so nobody could have accurately communicated the risk.
"2. A portion of the operation will be conducted inside an experimental submersible vessel. The experimental submersible vessel has not been approved or certified by any regulatory body and may be constructed of materials that have not been widely used in human occupied submersibles."
I don't know. This implies a high probability to me.
It's not quantified though. Also, it's pretty bad engineering practice to rely on implied risk; it's much more preferred to explicitly state your risk assumptions.
E.g., one of the problems with the Shuttle disasters is that the implied risk was understood differently at various levels. (Making numbers up here but directionally accurate) After the fact, managers thought there was a 1/1000 risk of catastrophic failure while engineers put it a 1/172.
The sub had already completed a few dives to the titanic and the CEO downplayed the risks in the texts that came out between him and a guy that pulled out. Taking both of those together I can see why a non-technical person might be taken in and therefore dismiss the waiver as typical legalese.
Do those waivers also mention the experimental vessel, explicitly disclaim that any regulations or certifications were followed, and that the construction materials are untested for the intended use?
>2. A portion of the operation will be conducted inside an experimental submersible vessel. The experimental submersible vessel has not been approved or certified by any regulatory body and may be constructed of materials that have not been widely used in human occupied submersibles.