They have small catamarans, paddle boats, kayaks available. That is the dive shop right on the Riu Palace property. These are included in your package. You can also rent jet ski but make sure you hagle with them about the price. The club has its own equipment. The dive shop at the Riu is called Scubacaribe. They operate out of many Riu resorts in the Caribbean. They also have PADIs highest rating in Negril.
As for room numbers, oceanfront, its been awhile since our last stay, seems like building 3 or 4 or 6 but its been too long ago, maybe 4108 or 6106, both oceanfront, 6106 is a suite.
Edited: 8:24 am, September 10, 2013