I am in Bequia now if I can help with any questions,I will try.
ENJOY, tomorrow night is Keegan's BBQ. A do not miss while on Bequia! Please write a follow up review of Your visit for those of us who can't be there :-)
For someone visiting for the day from a cruise ship, what currency would be accepted by local restaurants and taxis? Is it USD?
EC Dollars. Banks will not accept US currency unless it is pristine. Some merchants might take the US, but it is getting more difficult.
Though most restaurants will take credit cards other than AmEx - just check first. Taxis probably not.
For a one day visit US is fine unless You already have EC. Just be sure to check your bills. If there is a tiny hole, a heavy fold, any tear or writing on the bill You will not be able to use it. Use worn bills elsewhere. Very few places you will visit that do not accept a credit card. Taxi Drivers will want cash.
How is the sand flea situation?
If there are sand fleas on your currency, most taxi drivers will not accept it.