The main language spoken is Spanish.
Ecuador uses the US dollar, so any conversion from your home currency will be on that basis. The US dollar is accepted everywhere and the prices are generally quite low.
You may exchange money in Guayaquil and Quito's airport.
ATMs are available at most banks in Ecuador. Check with your bank before leaving home for bank names and locations participating in your ATM system. Also, if your "PIN" number is longer than 4 digits check with your bank to see if you need a new "PIN" code to use overseas. Amounts available for withdrawal in one transaction in Ecuador may vary from the amount your bank allows you to withdrawal in one day and several transactions may be necessary for larger amounts.
On Board: Cash and major credit cards are accepted on board (Visa, American Express, Master Card, Diners Club). A bill will be created for your bar and boutique expenses, as well as for the rental of the snorkeling equipment. You may pay your bill the night before or the morning of disembarking. If you decide to pay by credit card, they will need to run your card upon arrival to receive authorization (which takes 48 hours) and prepare your voucher.
Only global cell phones will work and only in the bigger towns. You may want to consider renting one or getting a satellite phone.
You may want to rent a cell phone in Ecuador.