My family takes regular trips to the Caribbean, and I always bring along my DSLR. I have never been able to accurately capture the blue of the water. 

Equipment:  

Canon Rebel XS (2008)  

Lens: EF-S 18-55mm 1:3.5-5.6 IS   

UV filter on the lense

I usually shoot at F4.0 on aperture priority. I've tried different white balance settings (the built-in cloudy, sunny, and AWB), and removing the UV Filter. I generally shoot in JPEG.

My photos always turn out washed out.  

Mid afternoon photo: [http://i.imgur.com/Jzsj8gW.jpg](https://i.imgur.com/Jzsj8gW.jpg)  

Later afternoon photo: [http://i.imgur.com/dE5iwlW.jpg](https://i.imgur.com/dE5iwlW.jpg)

The actual blue water in these photos is very rich and almost day-glow. 
Almost like this photo (which seems to be over saturated, although the ocean color is true to what mine should look like)
<http://www.caribbeanphotographyservices.com/images/photography-production-caribbean.jpg>

Photos at home (outdoor green spaces) and elsewhere the colors look good. It's only when I get around this blue that I have a problem. 

This photo has good greens, sky looks perfect, although the water is darker than in real life  

[http://i.imgur.com/9E7gqlZ.jpg](https://i.imgur.com/9E7gqlZ.jpg)   

* What are some things I can do to bring the blues out?
* Is what I'm expecting done mostly in post processing?
* Should I be looking for a polarizer?

Looking for any advice that I can find. 

Thanks!