Pesos?

[Kat]

My U.S. dollars were always accepted. I went to some very out of the way - non tourist places. You will usually get pesos back for change. They often apologized for giving change in pesos but we always accepted them with 'No problemo' & a smile and everyone was happy. I did have a little trouble with travelers checks. Some of the locals told me that the banks will refuse them if the signature does not match perfectly.
A night of drinking is a good example of 2 different signatures.

 

[crispos]

I think dnhill has it right. With the peso at 11.28 to the dollar a couple of days ago, most places are probably still working on 11 or even 10 for a USD. if you use an ATM you'll get pesos and you won't lose 5% or even 10% every time you pay for something, in usd. it adds up.

The dive operators want usd because they are used to a falling peso and therefore they protect their prices that way.
It's typical of any southern destination with a currency that is usually weak. Having said that, the USD has just come out of a weak period, so in some places the local currency has gone up.

I always bring back a couple of hundred Mexican Pesos so I have some for the airport taxi to downtown, some groceries or some dinner, as flights from Toronto come in at night.