The problem with anchorages here is depending on the time of year they are not useable-
Radio Bay in Hilo is useable pretty much all year round but you can't stay at anchor more than 90 days-and there is still a fee- there's really no where else on the big island you can go to easily all year round- After 90 days you have to move and sailing between the islands is demanding-
There are more options on Oahu- you can use one of the mooring balls in Kaneohe Bay depending on the size of your boat you can go transient from anchorage to harbor for a few months but then what do you do?
You kind of have to have a long term plan or you will be stuck...
Author & Sailor