Although I know Doppler personally, that's not the rule number 1 I was thinking of.....but they're all rules I do live by. 
I think I'm gonna pass on this one

I think I'm gonna pass on this one

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H2Andy:i am a lawyer, though i don't do personal injury cases, and this sounds very fishy to me.
to be liable to someone, you have to (in simple terms):
1. owe them a duty of care
2. breach that duty; and
3. cause them damage through your breach
now, if you are a DM on vacation, and some guy in your boat gets hurt,
and you have nothing to do with it, how on earth can you owe him
a duty of care?
the bad side is that if YOUR buddy gets hurt, you better believe that
lawyer is going to harp on the fact that you were a DM and owed
their client a higher duty of care. everything you did is going to
get scrutinized to see if you breached your duty.
miketsp:If you travel the rules may change a lot from country to country, which is why most of my more qualified friends only show a basic c-card when on holiday.