It all depends on what you want to be near. If you want to be near Old Port Royale the food court and pool then ask for Martinique or Trinidad North. They are the closest. It is nice to sit lay in the hammocks at Martinique and watch the Illuminations fireworks at 9 PM.
I think the water view rooms are a disappointment. Since you don't have private balconies you tend to keep your blinds closed, when you close them then you can't see the water.
Also the second floor would probably give you a better water view.
The resort is beautiful. You will have a great time. You might want to read the CBR FAQ thread listed below for more CBR info.