I found a single google result for Cayse Blanco, and it's treasure related: http://www.piratetreasureisland.com/island_location.htm . A better image of the map and some more background can be found here: http://thegreatlosttreasure.info/Page5.html
Good discovery. This might help with the treasure hunt.
We should all work together and split the prize
inb4 hidden paper wallet in the middle of the atlantic ocean with 5 btc in it