Almost all the harbours have shower and toilet facilities, usually attached to a taverna. Most charge between 2 and 4 euros for a shower unless you eat in their restaurant. Water for the yacht is easy to come by in most harbours, we find it best to fill up whenever you see a convenient hose rather than leave it till you run out. If you are moored outside a taverna it is polite to at least have a drink there. If you are on a pontoon or a lazy line then you are usually expected to eat at that taverna in the evening or pay a fee for mooring.