Not sure if I should carry coins for public transport in Nauru or if card payments are common. Advice?
I can tell you from my trip that you won't be able to use a credit card for public transport in Nauru. There is no bus system, and the taxi drivers only take cash. You must bring enough Australian dollars with you to cover your expenses, as the only ATM on the island is not very reliable. My advice is to have a good supply of cash on you for your entire stay.
When it comes to public transport in Nauru, it's cash all the way. It's not a place where you can rely on digital payments or credit cards. The traditional taxis and private cars all operate on a cash-for-service basis. Negotiate your fare upfront and make sure you have small bills of Australian dollars to pay. This is the most reliable and common way to handle all your transport needs.
My experience on Nauru was that a credit card is pretty useless for getting around. The taxi drivers will only accept cash, Australian dollars. My best advice is to carry enough AUD in cash for your daily needs. The system is simple and straightforward, but it is 100% cash-based. The taxi drivers will expect cash for every ride, and there are no public buses or other transport options that accept cards.
You must carry cash for public transport in Nauru. In fact, there is no formal public transport system at all. The only way to get around is by taxi, rental car, or by hitchhiking, which is common. The currency is the Australian dollar, but credit cards are not widely accepted, even at the only ATM on the island. It is essential to bring enough cash with you for your entire trip, as the Menen Hotel ATM can often be out of cash.