want to stay in an overwater bungalow or a water villa, you most likely are going to want to head to either the South Pacific (Bora Bora, Moorea, Tahiti etc) or the Maldives, which is just southwest of India. There are nearly 30 resorts with overwater bungalows in the South Pacific , and over 75 with water villas (as they are usually called there) in the Maldives. Between these two places you'll find literally ALL of the best overwater resorts in the world.
In many ways these two destinations are quite similar, but in many other ways they are very different. We'll discuss all of this below so you can choose which is the best destination for you.
Looking for over water rentals for around 300.00 a night
Candace,
Our other site has an updated list of the cheapest overwater bungalow resorts in the world. The ones in your price category are mostly in Asia. Unfortunately there are none around $300 near Tahiti or Mexico. -Roger