The unnamed island on the map the Chief points to is the southeast corner of the Dominican Republic, with the island of Puerto Rico in plain view to the right of it. The given longitude of 68° is about right, but the 36° latitude is much further north, closer to the island of Bermuda.
The bird call Max is trying to identify in the opening sequence is the call of the Australian kookaburra.
The admirals are John Nelson and Horatio Jones. This apparently is punning on Horatio Nelson and John Paul Jones, perhaps the most famous admirals in the naval history of Britain and America, respectively.