Will my I watch work in Cuba?
I Am traveling to Cuba. Will my iwatch function there? I understand I will not have cell service.
Apple Watch, watchOS 2.2, null
Your watch will function in 'stand-alone' mode. It depends on whether or not your iPhone is configured to work in Cuba which your post suggests is no.
You might consider having your iPhone enabled for 'roaming'... i.e. working in countries away from your home base.
See this article for more details.