I take the photocopies with me for identification. I believe the rule is that you have your passport with you, but am not sure. A photocopy seems like it would be good for ID and if they pushed it, you could always provide the one in your safe within a short period of time. To the OP, we don't take a lot of cash to the island since we spend most of the time on the beach where the resort provides chairs. We get groceries from Grande Marche to maximize beach time. We do eat out a few times in the evening, but usually spend time with friends doing what we do best - talking.