I've been known to wear hidden money pouches. there are some that strap to your leg, others that are enclosed in a belt. check out this site for more ideas:

www.preparedness.com/legpouc.html

I always carry 2 wallets.A sacrafical wallet with a small amount of cash , that I keep only walking around $ and some old or look like credit cards in. If you get robed give it up. and the $5 watch that you should have, ( if you're not fluent in spanish get one with a calculator so you can punch in the amount in question, saves a lot of miss-understandins / scams) exept of course in Pan, - US do;;ars
Make coppies of you pasport and id. if you loose the org. you can go to the U.S. consalute for replacement.
The pack is a problem if you're not in a motel, hostel etc. Some bus stations and airports have day lockers larger airports, most lickly). I carry a small fany pack with only the esentails in it. including the COPIES of my id.if the cops want the org. you can tell them about your pack, or that you lost them and are waiting for the consalute to get you new ones.
most motels have a desk safe, put the goodies there, or pay the extra for use of the room safe. You can also get small portable safes with short heavy cables to atatch to what ever. ( ment for travelers)
I also always keep 3 stashes of id, money and back-up travelers chcks. in 3 places. 1 in my real wallet, one in my pack and 1 hidden on me , or hidden in my foom. Worst case senerio.. they won't find all 3. This may all seem a little much, but I was traveling in some very bad aireas, better safe than sorry in any event.
But I have to question the ATM issue, Mine worked even in VZ. but you pay a hefty price.

We take our $$$ in mostly American Express travelers checks, which are widely accepted around the world, and some cash (denominations depend on the exchange rate - more smaller bills - $5s and $10s if the dollar is strong compared to local currency, more $20s if it's not). We never expect to find ATMs anywhere, although we do take a credit card or two.

I strongly second making a copy of your passport, other picture ID and ALL of your travelers checks (b/c if they're stolen, the company often asks what the check #s are). There are also receipts of your travelers checks (like a carbon copy) of each check, so be sure to separate these from the checks themselves after you sign all of your checks the first time and stash somewhere safe and away from the originals.

My husband uses a waist belt that goes under his waist line of his pants to carry his cash, cards and passport, and I use one that goes around my neck and under my shirt. You may want to get a small waterproof bag from REI or a paddling sports company (like Northwest River Supply) for your aquatic outings. If you're traveling alone, I'd recommend spliting your money supply into at least two stashes in case one gets lost or stolen (e.g. a money belt on your body and somewhere in your carry-on luggage -- not your checked bag).

Have fun!