On the boat I use only non electric solutions which were already mentioned:
For the coffee - a macchinetta such as the Bialetti. I also got as a present one of those pump based machines (pour in hot water, pump manually to produce pressure) which takes both capsules or ground coffee, but although the result is very good, it is a bit cumbersome for operation.
For the milk - a manual frother. I have one which I purchased in Italy but I found that a very good solution is also the Bodum type coffee press - they have a single cup size so with the same piece of equipment you can either make pressed coffee or froth milk.