Bottled water is available in the stores in each hotel and in markets. Clothing - Carry a light jacket for evenings. Men seldom, if ever, need a sport jacket as dressing is very casual. Neither men nor women are often seen on the streets of Havana in shorts except during the heat of summer, but shorts are common in other areas all year. Air conditioning can be a problem.
Women do wear pants to synagogue in Cuba.
Women can comfortably wear talit and kippah in congregations in the countryside. Be prepared for occasional rain in the winter and lots in the summer and early fall. Swimming is good all times of year. Most of the hotels will have pools. Bring bath towels for the beach that you can give to a friend before you return to your home.