I would have to disagree with StuartT about DM's wearing 7mm suits. That's simply not the case. 7mm would be too thick, too restrictive and would require too much weight to sink. The water is warm here. Right now it's pushing 80F.
The questions I would have to ask you are: "What size are you? How tall? What do you weigh? What is your body type? Most of my average sized Male clients (5'8" to 6', 180lbs to 210lbs) wearing a full 3mm suit will do just fine with 14lbs - 16lbs. Taller, heavier guys need 18lbs, sometimes 20lbs. Shorter, thinner guys wear 10lbs or 12lbs. It is rare that I put any more than that on them. I have only used 22lbs or 24lbs on guys when they are very big.
Average woman, 5' 5" to 5' 8" will wear 12lbs to 14lbs. Full figured ladies may need to add 2lbs to 4lbs to that. Smaller ladies can get by with 8lbs to 10lbs.
If you are in doubt, bring a bit more in small increments and you can ditch a lb or two if needed. Drop it or hide it under a rock and grab it on the way back. If you still don't have a good idea on what you will need, hire a local guide for your first dives here. Be sure to take note of the weight you used and decide if that was good or not and PUT IT IN YOUR LOG BOOK. I can't tell you how many divers I've met that have NO CLUE how much weight they need or how much weight they used on the boat yesterday...happens all the time...
And most importantly, "Have Fun!"