No. Buying a new camera will give you the same results. You need to learn how to use the camera, whichever model you have.
Check out the Sticky at the top of the UW Photo area (follow the Pink Link in my sig) for some tips on how to get better photos. Note that your SD camera does not have manual controls so you won't be able to use all of the tips in the Sticky, but there is still a lot there to help you. Here are a couple of quick fixes:
1 - get as close as possible to your subject. Distance is the enemy underwater as both depth and horizontal distance eat your light. And all photography is light. know your minimum focus distance and try to be that close for your photos - any closer and the camera will not be able to focus.
2 - use your internal flash when you are 3 feet or less away from your subject. If you are farther, switch to manual white balance.
3 - learn how to set your manual white balance (I think this model has this option, but you'll need to double check.) If you do not have manual white balance and are too far, or in conditions unsuitable, for internal flash, then experiment with the presets for white balance to see which is more pleasing.
4 - buy a strobe. Again, photography is light and if there isn't enough underwater you'll get blue photos (or green depending where you dive!) so the best option is to bring light with you. Expect to pay more for a strobe than you did for the camera and housing.
Have fun and keep practicing.