Not anymore, but the tap water is safe in Jamaica. Even when they had water bottles, I've always drank tap water at CN. Jamaica is not a great recycling country, and the ocean "garbage patches" are big enough already.
They sell bottled water in the gift shop at CN. If I remember correctly, it was about $1.00 per bottle (maybe 24-ish ounces ?? -- only a month ago & the memories fade so fast !!). And, it's not in a cooler; they store it in the glass case under the checkout counter, so you have to ask them for it.