ROPE - I have not heard of this snorkeling problem

[Trilobite]

Yeah, I read this elsewhere and was curious what the actual incidence is that you'd be warning people of. Based on those lose numbers it would be around 1/200,000. People can still get this even after acclimating a fews days. If you told me about ROPE and it was 1/200,000 risk the day I arrived or 1/500,000 if I waited a few days I'd still go day 1.

Of course, it is highly unlikely that it strikes randomly; so you wouldn't decide what to do based on the simple ratios you cite (assuming the figures are accurate--personally I'm skeptical half the visitors do significant snorkeling). The Hawaii study lists several risk factors:

RISK FACTORS​

• EQUIPMENT: Snorkels with a higher degree of resistance to inhalation​

increase the risk of ROPE​

• HEALTH: Heart conditions are significant risk factors., in particular diastolic​

dysfunction, which is an asymptomatic condition common in middle age​

people. A medical history of high blood pressure may be an indication of​

diastolic dysfunction.​

• EXERTION: Increased exertion can precipitate or accelerate ROPE.​

• RECENT EXTENDED AIR TRAVEL: It is possible that recent prolonged air​

travel may be a risk factor.​

• BOATS: When jumping into the water from a boat there is little time to​

acclimate to the equipment, temperature, and conditions, and, once in, the​

snorkeler can’t touch bottom so must exert extra effort. These are all risk​

factors so extra caution is advised.​

Many visiting snorkelers are likely kids who may have little risk of this condition. And many who snorkel won't be doing it shortly after air travel. So eliminating those two big chunks likely significantly increases the incidence right off the bat for those in the victim's position.

 

[smashweights]

Of course, it is highly unlikely that it strikes randomly; so you wouldn't decide what to do based on the simple ratios you cite (assuming the figures are accurate--personally I'm skeptical half the visitors do significant snorkeling). The Hawaii study lists several risk factors:

RISK FACTORS​

• EQUIPMENT: Snorkels with a higher degree of resistance to inhalation​

increase the risk of ROPE​

• HEALTH: Heart conditions are significant risk factors., in particular diastolic​

dysfunction, which is an asymptomatic condition common in middle age​

people. A medical history of high blood pressure may be an indication of​

diastolic dysfunction.​

• EXERTION: Increased exertion can precipitate or accelerate ROPE.​

• RECENT EXTENDED AIR TRAVEL: It is possible that recent prolonged air​

travel may be a risk factor.​

• BOATS: When jumping into the water from a boat there is little time to​

acclimate to the equipment, temperature, and conditions, and, once in, the​

snorkeler can’t touch bottom so must exert extra effort. These are all risk​

factors so extra caution is advised.​

Many visiting snorkelers are likely kids who may have little risk of this condition. And many who snorkel won't be doing it shortly after air travel. So eliminating those two big chunks likely significantly increases the incidence right off the bat for those in the victim's position.

Right, my point is not the exact odds but rather the odds being high enough that if people were warned they would feel confident taking the risk.

 

[Trilobite]

Right, my point is not the exact odds but rather the odds being high enough that if people were warned they would feel confident taking the risk.

My point is not the exact odds either; it's that the odds can easily be dramatically increased if you actually read the proposed warning (rather than make calculations based on dubious data) and see that risk factors apply to you, so the victim in this case may well have decided to wait a few days if he had known of the warning. (Just as people don't go running around in open fields during thunderstorms even though the risk of being hit by lightning is quite small on an absolute basis.)