Hello there, Mr. tropical_tom!
Like you I am planning to go to Cuba to scuba and chill out, but unfortunately not in January.
From what I've gathered so far, there are two outstanding places to go diving:
There's an island just southwest of Havana named Isla de la Juventud which seems to be well organized and popular for diving.
There's also an archipelago covering a big area on the south coast exquisitly named Jardines de la Reina boasting a great number of sites. This area was also covered recently in the National Geographic magazine. I can't remember which one, but it was this year.
For me these are the two places which stand out at the moment.
There should be other places too, but I haven't found out much yet. There is one place which, according to one person, is not so good; Chivirico. Supposedly, there is substantial pollution there making the reef decaying.
I must stress though that I am only referring to what I've been able to look up on the net and I have no first hand knowledge.
The following are links I found when surfing. Might be useful:
There's a useful map here linked up with info on dive-operators as well as some divesite info:
http://www.cubalinda.com/English/Activities/ScubaDiving/ScubaDivingZones.asp
Lots of info on this one. Check out the forums:
http://www.cubamania.com/
Good article:
http://www.skin-diver.com/departmen...beanAndBermuda/Cuba/mar01_cuba.asp?theID=1432
There is probably a lot more out there, but Cuba does't seem to be 'on the net' just yet, at least as far as diving is concerned.
If you don't mind we could try and share info. I'll forward anything good I can find if you like.
Best wishes
René-Marc