"Peter HK" wrote in message
...
I'll give my opinion for what it is worth.

I'm a physician in Geriatric and Internal Medicine in Australia.

From what describe, if accurate, your father likely has Alzheimer's
disease. While many would question giving a diagnosis over usenet, it's
not a big call as Alzheimer's is the commonest cause of dementia by a
large margin ( about 3/4 of all cases at that age) and affecting about 25%
of 85 year olds. The lack of judgement and forgetfulness you describe is
typical. Many are under the mistaken impression that these are a natural
concomitant of aging but that is not the case- Three out of four 85 year
olds are cognitively normal.

While I know nothing of your medicolegal systems (I'm assuming you're in
the US), here, the appropriate step would be a medical assessment to make
or refute a diagnosis and if he is suffering from Alzheimer's of
significant degree, and thus not have decision making capacity, then take
the suitable steps to protect him and others from harm.

Of course if he does not have a disease like Alzheimer's affecting his
cognition and is simply a foolish/stubborn/cantankerous old man then he
and his friend can accept any risk they choose. Playing the odds, I think
the likelihood is a dementing illness in the early stages.

Unfortunately we see quite commonly the effects of Alzheimer's disease too
late to intervene. Many a family business has been ruined by bad decision
making from dementia before it is picked up, leaving the spouse
destitute.

I do go sailing as well - hopefully the off topic post is excused.

Peter HK
IF you're a doctor, and IF he's got Alzheimer's, how is sailing going to
make the rest of his life any worse? If his girlfriend is 60+ she's old
enough to make her own mind up. Is it the father's happiness the daughter's
worried about, or her inheritance going on a boat and a girlfriend.
Chances are, that at that age he'll be so tired in a week or less that he'll
tie up somewhere and live happily ever after in port. If he dies at sea, so
what? It's how he's chosen to go, and at 85 what else has he to look forward
to/