Below is the earliest reference to a possible Spanish map that I am aware of and it is fringe at best.
1906 - The Lure of the Pirate's Gold by Josephine Freda
As I've pointed out on a few occasions here, my research points to the Fredea story as being a slightly garbled account of the first published record of a set of seven treasure maps that were to resurface thirty years later as the so-called Kidd Maps, which were at that time in the hands of a group of dilettante treasure hunters.
The earliest record the group had of the treasures they were looking for dated back to the mid-18th century. They believed that the island in question was Juan Fernandez - which explains why the present outlines of these maps bear such a close resemblance to 17th and 18th century maps of that island.
The outlines we see today are not original, and from correspondence in my possession it becomes clear that it was Harold Wilkins who correctly identified the island as Des Barres' Gloucester Island in Mahone Bay and that, thus, all seven sets of cryptic instructions very likely pertained to Oak Island. There was no suggestion at all that the instructions had anything to do with pirates. Wilkins tried to get a concession on the island in the late 1940s, but the consortium broke up. He kept very quiet about this, but the details are in his correspondence.
We only have five sets of instructions, but these identify points on the figure below which is from a pure geometrical construction that places the Drilled Rocks, the Welling and Mallon Triangles and the Money Pit:
View attachment 1705732
The instructions all conform to a common format:
Identify three points of a triangle offset from the features noted above (Pit, Rocks, Triangles)
Form a triangle and find its centre
Take an offset (generally in the form a + b + ac in the direction of the centre point of the design
Note that the Tree in all cases is actually the centre of the Money Pit. For example, one map gives us:
(Read the first two lines in reverse.)
18 NE by 71 W on Rock -> Rocks; 71W and 18NE
26 ENE by 18 SW Palm -> Tree: 18 fathoms SW and then 26 fathoms ENE
7 feet by 7 feet by 8 -> 7 feet + 7 feet + (8 x 7 feet) = 70 feet (towards the central point)
Meaning: Identify a point 71 fathoms west of the East Rock, a point 18 fathoms northeast of the West Rock, and a point 18 fathoms southwest of the Money Pit thence proceeding 26 fathoms ENE. Find the centre of the triangle thus formed and proceed east for 70 feet (7 feet then another seven feet then eight times seven feet). This spot is the third from the left in the above diagram.
The two Palmer maps are fourth from the left (topmost - 3 feet by 3 feet by FOUR = 18 feet) and sixth from the left (360 yards V.R. North). There is no map for the Cave-In Pit, but it’s interesting that somebody dug a hole some 18 feet deep at that point and then filled it in.
The maps are so disparaged by all and sundry that the truth about their origins is readily dismissed without a second thought. People claiming that no sensible and rational person would credit such a background to Oak Island simply ignore the fact that the originator would not have thought about things the same way as we do. Those claiming Oak island is a hoax will simply state that the maps' instructions all work mathematically purely by accident.
These are all highly sophisticated mechanisms for identifying precise points in a pattern on the ground (to within a foot of target) - it’s not the work of your average pirate. If you’re at all interested in the underlying geometry and the detailed workings of the instructions then you might wish to take a look at a web site (link below) that I prepared many years ago before publishing my Oak Island books:
Maps, Mystery and Interpretation
It's not really necessary to have an understanding of geometry and trigonometry, but this could be an interesting school project in math and history.