Two years ago I shipped a very large painting (3X4.5) to the US from Sydney
as excess baggage and it was only about 80.00. However, before I decided to do that I found a few freight forwarders online that will ship your excess luggage not too unreasonably. They were Australian firms. A quick search turned up Excess baggage, unaccompanied luggage, worldwide, by sea freight or air freight.
as well as Austrian: Baggage Fees and Policy - SeatGuru
which has a database of airlines and suggestions on how to avoid excess baggage fees
. I have not personally used these sights. You might try posting
it if the postal service
will hold for pick up (what we call in the states general delivery) or direct to the marina if they will hold it for you. You might also check with local moving firms if you have a lot of stuff as usually if there is room you can get in a truck with someone else's stuff and only be charged for the amount of space you use (at least in the state's you can). Hope it works out for you.