That year we had planned to fish for marlin off the Cuban coast for a month. The month started the tenth of April and by the tenth of May we had twenty-five marlin and the charter was over. The thing to have done then would have been to buy some presents to take back to Key West and fill the Anita with just a little more expensive Cuban gas than was necessary to run across, get cleared, and go home.
Could anyone explain to me the meaning of the last sentence? What does the expression 'to run across' mean here? And do the words 'get cleared, and go home' go with 'necessary to' or with 'The thing to have done then would have been to'?
I suppose, 'Anita' is the name of the ship.