First thing I would do is go to my banks website and read up the FAQ section about debit cards.
First, most of us have a far far higher credit limit on our credit cards, than we have deposited in the account linked to our debit cards. That can be an issue if you make purchases at stores that put a hold on your funds in excess of your purchase. They do that without your knowledge. I just ran into that this week here at home. I had a gas station accidentially put a $150 hold on funds on my debit card....and I only had $151.80 in the account (thank god today is payday). Because I complained, the bank reduced the normal 7 day hold time frame to 4 days. As the bank point out, they did this as a courtesy because I was a "valued" customer. They normally don't waive a 7 day hold. That could cause big problems.
Second, the consumer protections on a debit card are usually far far less than on a credit card. If there is an issue with that expensive jewelry you bought, your credit card company will go to bat for you. Few debit card companies will do that.
Third, there may be daily spending limits on a debit card, or daily limits on how much cash you can get. My cousin ran into that during a trip to
Disneyland. Have you ever tried to feed a family of 6 at Disneyland on $100 a day? With no credits cards, no cash, no travelers checks, just a debit card?
So my first advice is do some research. As for me, I wouldn't use a debit card on a trip. In the spirit of full disclosure, I didn't even START using my debit card for anything other than taking cash out of the ATM until 6 months ago. If I had continued to pay cash for gas I would not have had the problem I had. And I like the day or two float a check allows me at the grocery store.