AD AUGUSTA PER ANGUSTA
When, at Carusburc, you will have Albion in the back,
Look for the Opening that reveals the Celestial Light.
Do not wait, do not ask for your rest, But get ready to walk on the water.
Twice, Neptune will come to your rescue And lead you away from the icy Septentrion.
Pursue your way and do not interrupt your journey
Before seeing through the opening, the becalmed Nave.
Without deviating an inch, draw a line, and you will not regret what you did.
Solvability: 
We start in Cherbourg but don’t have much clue what happens next!
This clue begins in Cherbourg (old name Carusburc) with England (old name Albion) behind us, then a long route is described, involving a few mysterious locations including the ‘Nef Encalminée’ the enigmatic becalmed nave.
How the solution is reached
Only a few elements of this clue are understood. We know we begin in Cherbourg and the opening is almost certainly Bourges, the city found in the clue entitled ‘Opening.’ Walking on water may refer to drawing a line through the blue of the map, particularly as the clue image reflects this. We see ‘the becalmed nave’ through the opening, but what is this feature or place? We are instructed to draw a line from Bourges to the nave.
The visual
The picture shows a pencil drawing a line at an angle, perhaps it suggests a south-west direction from Cherbourg. The waters open and reveal a shell. It doesn’t seem like the image will help us solve this enigma.
Points to consider
A couple of the french words used in this clue have multiple meanings. Septentrion is a complex word that usually means North. “Without deviating an inch” uses the word “pouce” which can be translated to “inch”, but could also be translated as, “Without deviating from a thumb.”
The phrase ‘Nef Encalminée’ could refer to the kind of ‘nef’ which is medieval metalwork in the shape of a ship.
Cherbourg is listed in the 10 towns of the 580 enigma, as is Bourges, though it is not clear whether that is relevant.
‘Seek the Opening that reveals the Heavenly Light’ may refer to the ‘light from the sky’ in Golfe Juan and the previous clue. A line connecting Cherbourg, Bourges and Golfe Juan is perfectly aligned.
We start the clue with our back to England, so we are looking inland. Yet the helpers of Neptune suggest crossing the sea. Some people think the visual clue gives the direction to take, drawing a line southwest at a 45 ° angle towards the Channel Islands. Perhaps the shell represents an island?
We ‘persue our way’ and ‘do not interrupt our journey’ then the next stage of the clue has us at the ‘Opening’ (Bourges?) seeing the ‘Becalmed Nave.’ No one seems clear how we get here from the sea, or what the nave means. However if we ‘see’ the Nave ‘through’ Bourges, that suggests it is east of Bourges.
Some people believe the ‘nave’ of this clue and the ‘Black Perched Ship’ of the 600 are one and the same place. Max connected them in an additional clue, but he didn’t say they were the same place.
At the end of the puzzle we find the Nave and draw a line joining the ‘opening’ and the Nave, this is a line we ‘will not regret.’
The next clue 650 begins on a precise place, so presumably it is the end point of this clue, most likely the ‘nave.’ The madits tell us that “nothing slips between the 560 and 650”, they follow each other perfectly.
This clue’s title is a Latin phrase that means, “to great results by narrow ways.” It’s possible the phrase adds some detail to assist with the solution.
This clue uses archaic words for the place names, but why? Albion recalls the time of King Arthur, does this suggest this clue might link to the sword in the stone of the 470 enigma?
No one seems sure where the ‘Nef Encalminée’ is found. Is the ‘becalmed nave’ the same place as the ‘black perched ship?’
We walk on water, Neptune helps twice, and we escape the ‘icy’ North, but what is our direction? This must be detailed somewhere in this clue or the previous clues. We appear to draw a number of lines in this clue with key places still enigmatic.
In August 2023 Michel Becker gave an additional clue showing an image of a line from Cherbourg, which appears to suggest we draw a line heading over the sea towards Spain. You can find the image, and a discussion of its relevance in the additional clues section.
In conclusion
We need to know the direction to take from Cherbourg, and how to connect the ‘opening’ with the unknown place ‘the becalmed nave.’ Some lines must be drawn on the map with this clue, but until we solve the ‘nave’ mystery this will not be possible. The next clue connects to this one, so to progress beyond this point it’s important to solve this enigma.
See also
The place revealed by this clue is well known, but how do we fly and land Apollo’s arrow?
The compass in the visual has no obvious explanation, it is used for drawing circles. The alignment of the planet symbols also suggests a circle.
An important clue to the path of the arrow was given by Max in his Tour de France additional clues. He revealed that the Tour de France cycle race crossed the path of Apollo’s arrow on July 15th 1993. On this day the cyclists travelled from Serre-Chevalier to Isola 2000 in the Alps. So it does seem certain that the arrow flies north from Golfe Juan, perhaps towards Carignan.
UT QUEANT LAXIS
There are many enthusiastic owl hunters who believe Dabo is the ‘spiral with four centres.’ Some even think this means the owl is buried in Dabo, rather than this being another town to add to the many scattered towns on the map.
WHEN AL-MAR ALLIES WITH PRENESTE’S FIBULA, DARKNESS SHINES
This clue is one of the main sticking points in this treasure hunt.
