As a sailor myself, this question is very interesting! El Nino is associated with less activity in the south Pacific tropical cyclone region, but of course it is always a good idea to keep an eye on the weather forecast. The Australian Bureau of Meterology tracks cyclones in this region, and they should have an outlook for the 2014-2015 season relatively soon. (They do an outlook specifically for the South Pacific Islands that may be interesting for your planning.) The reduced trades characteristic of El Nino are likely to hamper your progress, however.