I'm thinking of going to AC mid July. My sister is trying to talk me into learning how to scuba dive while I'm there. I've been to a couple of sites, and it seems like they said that it was a four day course for about $400. How difficult is this to do? (the actual process of getting certified and arranging to do this in AC) Any other advice would be appreciated. Thanks.

You might want to consider doing your class & pool work at a PADI scuba shop near your home and then get your Open Water Certification in AC - that way you only use two days on "school" and the rest on fun dives and other things. ;-)

The 4 day course is to become a certified diver, you also have the option of a resort course. A resort course will allow you to dive with an instructor to around 35'. You start with an instructional video, learn some basic skills, then you're off!
I'm a newly certified diver and the friend I went with did the resort course at Amigos del Mar. I tagged along for the instruction and we did our diving together. We were both thrilled with the experience.
The price was VERY reasonable.

I got my open water certification in early March with Reef Divers. You might want to do the " at home " CD-ROM version as I did first. Better hurry though. It's not something you just " blow thru." I highly recommend Reef Divers. Larry Parker has been there for 22 or so years. I'll be visiting and diving again there in late July! Can't wait! Good Luck!

Thanks everyone for the advice. I'm still not sure I will actually get there. LOL. And once there, what I'll do. But you've given some good advice. Thanks.

Talk to TULU -- he works off the CORAL BEACH dock ... in the middle of San Pedro ... he is a master diver who will make it the most fun .... for the least amount of money because he works for himself, not for a hotel. He is a Belizean with 30 years experience on Ambergys. The best.