Logbooks are essential to register for diving. There is limited rental gear and a shortage of spares in Cuba. Bring your own torches. A depth limit of 30m applies at Maria La Gorda. A minimum 3min stop at 3m is also stipulated at the end of each dive.
Credit cards have very limited use in Cuba.
It is better to take US dollars. Mosquito repellent, bite gel and a small first-aid kit are well worth packing. A doctor accompanies each trip, and blood pressure is frequently monitored.