take the water taxi from Belize City to San Pedro - you've got the time, it's a beautiful ride, a fun way to chat with locals and between the two of you you'll save about $150 over the cost of flying.

Pedro's Inn is the cheapest place to stay on the island (around $12 I think), fun bar, free internet and for a while he had a deal where you got free pizza as long as you were ordering beer.

You'll find differing opinions about cave tubing if you do a search - it will cost a lot less to go from the mainland - same for the ruins - if you're only going to one site see Lamanai.

You can rent snorkels/fins for about $5, a half day at hol chan & shark/ray alley is about $25 + the entry fee and worth every penny.

Good cheap food from the street venders and really good meals if you try some of the smaller spots off the beaten path.

You'll be hooked! Have fun!