There is also Ruby's laundrymat which is on the same east/west street that the main water taxi peir is on. If you arrive on the water taxi and just continue walking down the street, you will see it just past Habaneros, Rose's Cafe, and Creative Style Salon, on the left (south) side of the street.
It is a laundramatt with assistance. You can stay and take care of your own clothes for 4 bzd a load to wash and 4 bzd to dry or you can leave your clothes and they will wash/dry and fold them for a little bit more, like a dollar extra to wash and a dollar extra to dry and fold.
We use them to dry our laundry on these wet days when you can't hang towels out to dry. Its worth it to pay the dollar extra.