I think very, very few boats will be going eastward from
South Africa to
New Caledonia or
Fiji. It is just not a
route that has any popularity and is a difficult sail to boot. If you have lots of time and are not in a rush to go, you might be able to pick up a
boat going from
Cape Town to the
Caribbean. Once there you would need to find a
boat going to
Panama and hopefully into the Pacific in the general direction you want. Most boats, after doing the
Canal go to
French Polynesia often with a stop in the
Galapagos. From there, boats tend to go
New Zealand or
Queensland. You would want one of the latter since they typically go to
Fiji and may stop in New Caledonia.
Boats would leave
Cape Town in December or January generally. They have to check out at the Royal Cape Yacht Club. They might be able to post a
crewing notice for you. There are other places online you can post. How much experience do you have? If you are light on experience you might want to use the time between now and December
crewing locally (assuming you are now in SA). Good luck.