In South America and the Pacific try 12 and 16 mHz. In general, the farther the distance, the higher the frequency. Propagation really stinks lately. It is near the worst time of the eleven year sunspot cycle. Communications are still possible, but we will have to work a little harder.
Relays are one way to do that.
If you hear someone trying to reach us, try to relay - they are sure to return the favor some day. We are always glad to hear reports from customers about what frequency, and time of day, is working for your current location.