How is the diving at that time?
Every season has its reasons and delights. Suffice to say, if it is rainy, the viz can get icky. The critters don't care, but they don't like the cold fresh water. then you have to dive deeper accordingly. Otherwise Roatan is a little-critter shallow water dive 1:20 BT delight.
Which of the accommodations at Cocoview do you recommend?
They all work, Cabanas, Bungalows, On-Shore. We like the Cabanas (C1>12), I think they're cheaper. More privacy than the rest. The on-shore units upstairs, #13,14,15,19,20,21 are also very private, #17 is the darkest and coldest (my favorite as I tend to sleep a lot during the day and night dive all night. TSR is close by and has the only bathtub. The Bungalows are pretty and quaint, and they do have large beds, but they have zip for a front porch and if the reason you came to CCV was to not be at Fantasy Island, they Bungalows can be kinda close to that sonic nightmare, especially around holliday time.
how early should we book?
For Christmas/New Years I would suggest you call yesterday or sooner. CCV is generally sold out all the time, but some openings pop up around holidays. That family pressure jazz. Do not be afraid to get on a wait-list. If they put you in a Beach House, they're okay, too. Just 80-200 yards down a hard sand path to the main lodge. Still on the same small private island.
Are there any other activities besides diving that you recommend?Thanks!
Sleeping. And eating.