These are oceanic pilot charts
that are used for making and planning passages. They also point out great circle routes. Water
temperatures and currents and where your predominant high and low pressures should be. There is one for each month of the year to adjust for seasonal changes. You can pick them up from most marine
supply and chart suppliers. You have to order for which place in oceania you expect to be cruising in such as North Pacific
or South Pacific
. There are centuries of information in these charts and a lot of history
and other information. Have fun studying.